Search Results
Results 651 - 700 of 1861
< 9 10 11 12 13 14 15 16 17 18 19 >
Furlan Raffaello - - 2006
Previous reports suggest that inflammatory bowel diseases may be accompanied by abnormalities in the neural autonomic profile. We tested the hypotheses that 1) an exaggerated sympathetic activity characterizes active ulcerative colitis (UC) and 2) a reduction of sympathetic activity by clonidine would be associated with clinical changes of UC. In ...
Tutuncu Neslihan B - - 2005
The present study has been designed to determine melatonin levels in type 2 diabetic patients and test the relationship between the autonomic nervous system and melatonin dynamics. Thirty-six type 2 diabetic patients and 13 age-matched healthy subjects were recruited for the study. Circadian rhythm of melatonin secretion was assessed by ...
Holmberg Björn - - 2005
It is not known whether bilateral stimulation of the subthalamic nucleus, performed to improve skeletal motor control in advanced Parkinson's disease, also affects central autonomic regulation of cardiovascular motor function. Furthermore, reduced treatment with dopaminergic and other drugs after bilateral stimulation of the subthalamic nucleus could affect cardiovascular autonomic reflexes ...
Harada Takuma - - 2005
The effects of drugs on the QT interval should be evaluated precisely in the early stages of drug development because QT prolongation can trigger the so-called torsades de pointes, a life-threatening polymorphic ventricular tachycardia. It has been reported that the QT interval is affected by autonomic nervous tone besides the ...
Yasuda Gen - - 2005
OBJECTIVE: Few studies have assessed whether 24-h blood pressure control induced by antihypertensive agents improves macroalbuminuria in hypertensive type 2 diabetic patients with overt nephropathy. We evaluated the effects of losartan and amlodipine on 24-h blood pressure, autonomic nervous activity, and albuminuria in these patients. RESEARCH DESIGN AND METHODS: In ...
Piccirillo Gianfranco - - 2006
BACKGROUND: Early hypertension is associated with left ventricular diastolic dysfunction due to increased end-diastolic pressure. This increase, through the cardiopulmonary reflexes, can influence autonomic cardiovascular control. METHODS: We assessed autonomic nervous system modulation of cardiovascular signals by power spectral analysis of RR interval and systolic arterial pressure variabilities in subjects ...
Iellamo Ferdinando - - 2005
We tested the hypothesis that individuals with Down syndrome, but without congenital heart disease, exhibit altered autonomic cardiac regulation. Ten subjects with Down syndrome (DS) and ten gender-and age-matched healthy control subjects were studied at rest and during active orthostatism, which induces reciprocal changes in sympathetic and parasympathetic traffic to ...
Gratze Gerfried - - 2005
We hypothesized that the extreme endurance exercise of an Ironman competition would lead to long-standing hemodynamic and autonomic changes. We investigated also the possibility of predicting competition performance from baseline hemodynamic and autonomic parameters. We have investigated 27 male athletes before competition, 1 h after, and then for the following ...
Valipour Arschang - - 2005
To determine the dynamic effects of short-term nasal positive airway pressure (nPAP) on cardiovascular autonomic control, continuous recordings of noninvasively obtained hemodynamic measurements and heart rate variability (HRV) were obtained in 10 healthy subjects during frequency-controlled breathing (between 0.20 and 0.24 Hz) in supine posture under different pressures of nPAP ...
Bilan Andrzej - - 2005
Circadian pattern of heart rate variability spectral indices, including hourly, 24-hour, night, day, morning, and sex-adjusted measures of low frequency (LF), high frequency (HF), and LF/HF, was evaluated in healthy persons in 24-hour 3-lead electrocardiogram. HF showed circadian pattern with the greatest night values and LF/HF with the smallest night ...
Johansson Mats - - 2005
BACKGROUND: Impaired arterial baroreflex function has been associated with an increased risk of ventricular arrhythmia and sudden death. This has also been suggested for patients with chronic renal failure (CRF) who are at high risk for cardiovascular morbidity. The aim of this study was to investigate the arterial baroreflex function ...
Win Ni Ni - - 2005
Heart rate (HR) and arterial blood pressure (BP) changes have been reported during conscious sedation with propofol and midazolam. One potential mechanism to explain these changes is that propofol and midazolam affect HR and BP via changes in the cardiac autonomic nervous system. Two specific hypotheses were tested by HR ...
Yamanaka Nozomu - - 2005
Entropy (ENT) is a newly developed measure of the complexity of heart rate variability (HRV). The aim of this study was to characterize the complexity of HRV in patients with end-stage renal disease (ESRD) and to find a possible clinical utility. Healthy subjects and patients with ESRD undergoing hemodialysis (HD) ...
Shaltout Hossam A - - 2005
A blunted baroreflex sensitivity (BRS), impaired heart rate variability (HRV), and high plasma nonesterified fatty acids (NEFA) are predictors of adverse cardiovascular outcomes. We tested the hypothesis that elevation of NEFA negatively impacts the cardiac baroreflex response and undertook spectral analyses and molecular studies to delineate the mechanism of action. ...
Bertram Delphine - - 2005
The present study examined the effects of baroreceptor loading and unloading on the various rhythms present in the renal sympathetic nerve activity (RSNA) of 10 conscious rats. Short-lasting (4-5 min), steady-state decreases (from -10 to -40 mmHg) and increases (from 5 to 30 mmHg) in arterial pressure (AP) were induced ...
Hanss Robert - - 2005
BACKGROUND: Hypotension due to vasodilation during subarachnoid block (SAB) for elective cesarean delivery may be harmful. Heart rate variability (HRV), reflecting autonomic control, may identify patients at risk of hypotension. METHODS: Retrospectively, HRV was analyzed in 41 patients who were classified into one of three groups depending on the decrease ...
Casu Massimo - - 2005
OBJECTIVE: This study aimed to analyze the autonomic control of heart rate variability (HRV) in subjects receiving chronic l-thyroxine (l-T4) treatment after total thyroidectomy and (131)I therapy for differentiated thyroid carcinoma. METHODS: Blood pressure (BP) and sympatho-vagal activity (evaluated by power spectral analysis (PSA) of time-domain parameters of HRV) were ...
Sanya Emmanuel O - - 2005
Cardiovascular autonomic neuropathy has been previously reported in patients with multiple sclerosis (MS) using standard reflex tests. However, no study has separately evaluated both parasympathetic and sympathetic cardiovascular autonomic regulation. We therefore assessed the baroreflex-mediated vagal and sympathetic control of the heart rate and sympathetic control of the blood vessels ...
Motte Sophie - - 2005
Heart failure is associated with autonomic imbalance, and this can be evaluated by a spectral analysis of heart rate variability. However, the time course of low-frequency (LF) and high-frequency (HF) heart rate variability changes, and their functional correlates during progression of the disease are not exactly known. Progressive heart failure ...
van der Veek Patrick P J - - 2005
Animal studies have demonstrated that visceral afferent stimulation alters autonomic cardiovascular reflexes. This mechanism might play an important role in the pathophysiology of conditions associated with visceral hypersensitivity, such as irritable bowel syndrome (IBS). As such, studies in humans are lacking, we measured viscerosensory-cardiovascular reflex interactions in IBS patients and ...
Campen Matthew J - - 2005
Heart rate variability (HRV) is a well-characterized, noninvasive means of assessing cardiac autonomic nervous system activity. This study examines the basic cardiac responses to hypoxic and hypercapnic challenges in seven strains of commonly used inbred mice (A/J, BALB/cJ, C3H/HeJ, C57BL/6J, CBA/J, DBA/2J, and FVB/J). Adult male mice, 8-12 wk of ...
Prakash E Sankaranarayanan - - 2005
1. In the present study, we tested the hypothesis that heart rate variability (HRV) is reduced in recent-onset hypertension and that pressor responses to standard autonomic reflex tests are not any different in hypertensives compared with normotensives. We also hypothesized that subjects with high-normal blood pressure (BP) would be distinguishable ...
Nacitarhan Vedat - - 2005
The effect of therapeutic ultrasound (US) on nervous system is controversial and the effect on autonomic nervous system is not clear. Therefore, the present placebo-controlled trial was planned to investigate the effects of therapeutic US application on right-side stellate ganglion, by using analysis of heart rate variability (HRV). A total ...
Ozdemir Ozcan - - 2005
Elevated sympathetic nerve activity in patients with mitral stenosis (MS) may be an index of the severity of the disease. Percutaneous mitral balloon commissurotomy (PMBC) is now a standard treatment for many patients with symptomatic MS. We aimed to show the effects of PMBC on autonomic nervous system activity in ...
Chen Shigao - - 2005
The dynamic performance of a new fibre optic sensor intended for measuring physiological fluid pressures is assessed in water. The sensor's sensitivity is evaluated at 23 degrees, 35 degrees and 37 degrees C against a Millar pressure catheter for sinusoidal pressure inputs with frequency ranging from 0.5 to 10 Hz. ...
Murata Katsuyuki - - 2005
OBJECTIVES: There is evidence that shift work contributes to excess cardiovascular mortality. The purpose of this study was to determine the effects of shift work on heart rate-corrected QT (QTc) and blood pressure in relation to heart rate variability (CV(RR)). METHODS: The study population consisted of 153 male shiftworkers and ...
Cooke William H - - 2005
BACKGROUND: Noninvasive procedures for predicting progression to hemodynamic instability during induced central hypovolemia in humans were evaluated. The purpose of this study was twofold: (1) to track changes in autonomic function induced by a model of hemorrhage, and (2) to determine whether measures of autonomic function are reliable without strict ...
Yoshii Masayoshi - - 2005
Only a little information is available for the evaluation of the complex hemodynamic changes that occur during hemodialysis. Recently, we developed the transthoracic electrical admittance cardiograph for repeated measurements of cardiac output, and monitored hemodynamic changes during hemodialysis by the use of this device. We measured cardiovascular hemodynamic and autonomic ...
Sothern R B - - 2005
Putative circadecadal modulations of a circannual variation in diastolic blood pressure are explored in a still accumulating 35 year record of self-measurements by a clinically healthy man. Analyses of monthly means by gliding spectra, one-way analysis of variance (ANOVA), and cosinor were carried out after removing data collected during travel ...
Pereda Ernesto - - 2005
We made use of multivariate nonlinear analysis methods to study the interdependence between the cardiac interval variability and both the respiratory activity and the systolic pressure in rats. The study was carried out in basal conditions and after the application of different drugs affecting the cardiovascular system. The results showed ...
Madanmohan - - 2005
The purpose of the present study was to determine whether readily measured blood pressure (BP) indices and, responses to autonomic reflex tests could be used as surrogates of short-term heart rate variability (HRV), which is an established marker of autonomic regulation of SA node. Therefore, we examined the correlation between ...
Jhun Hyung-Joon - - 2005
OBJECTIVES: Analysis of heart rate variability (HRV) is useful for measuring cardiovascular autonomic function. The effects of blood metals on cardiovascular autonomic function have not been studied extensively. The objective of the present study was to determine the association between the concentrations of blood metals, including toxic and essential trace ...
McGuire Kimberly M Beckwith - - 2005
We evaluated systolic and diastolic blood pressure, heart rate variability and skin conductance at baseline, and 1 and 4 months in 38 participants with elevated blood pressure, randomly assigned to expressive writing or control groups. There was a significant interaction such that the very low frequency wave of heart rate ...
Goncalvesova E - - 2005
BACKGROUND: Phenylethanolamine N-methyltransferase (PNMT) is an enzyme involved in the epinephrine synthesis. The aim of this study was to investigate PNMT gene expression in the transplanted human heart in relation to the time elapsed from heart transplantation (HTx) and selected clinical characteristics. PATIENTS AND METHODS: The messenger RNA (mRNA) levels ...
Berntson Gary G - - 2005
The root mean square successive difference (RMSSD) in heart period series is a time domain measure of heart period variability. The RMSSD is sensitive to high-frequency heart period fluctuations in the respiratory frequency range and has been used as an index of vagal cardiac control. By transfer function simulations, the ...
Hammer Peter E - - 2005
A mathematical model of the arterial baroreflex was developed and used to assess the stability of the reflex and its potential role in producing the low-frequency arterial blood pressure oscillations called Mayer waves that are commonly seen in humans and animals in response to decreased central blood volume. The model ...
Norton Michele R - - 2005
Fourier-based approaches to analysis of variability of R-R intervals or blood pressure typically compute power in a given frequency band (e.g., 0.01-0.07 Hz) by aggregating the power at each constituent frequency within that band. This paper describes a new approach to the analysis of these data. We propose to partition ...
Sawai Asuka - - 2005
We have developed a wristwatch-type heart rate (HR) recorder (WT-HR tachometer) with an acceleration-pickup sensor, which can record HR and body activity (ACT) minute by minute for a long time (> 120 h). To study its application, we compared these measurements with 24-h blood pressure (BP) and HR variability, sympathovagal ...
Figueroa Arturo - - 2005
The attenuated heart rate (HR) and blood pressure (BP) response to exercise in individuals with Down syndrome (DS) has been attributed to autonomic dysfunction, which has been associated with obesity. Our purpose was to determine the role of autonomic control of HR to the attenuated chronotropic response observed in individuals ...
Okano Yasuko - - 2005
Increased resting heart rate (HR) and increased sympathetic nervous activity are independent risk factors for cardiovascular disease. Recently, base heart rate (HRo: minimum stable HR during sleep) has been reported to relate to cardiac stroke volume and age. However, little is known about the relevance of HRo. The aim of ...
Gao Sinsia A - - 2005
Spontaneous baroreflex sensitivity (BRS), the reflex heart rate modulation in response to blood pressure changes (predominantly an index of cardiac vagal activity) and temporal QT variability (an index of myocardial repolarization) have been demonstrated to convey important prognostic information. The information about reproducibility of BRS and temporal QT variability is ...
Højgaard Michael V - - 2005
OBJECTIVE: Previous studies have indicated moderate-to-poor reproducibility of heart rate variability (HRV) but the reproducibility of blood pressure variability (BPV) and spectral measures of baroreceptor sensitivity (BRS) are not well established. METHODS: We measured normal-to-normal heart beat (RR) interval and finger blood pressure (Finapres) in 14 healthy individuals on three ...
Sanya E O - - 2005
OBJECTIVES: The aim of this study was to assess baroreflex regulation of the heart rate and blood vessels in migraine patients in comparison with healthy controls. METHODS: In 30 migraine patients who were in a headache-free phase, aged 34 +/- 2 years, and 30 healthy controls, aged 34 +/- 3 ...
Hidaka Syozo - - 2005
STUDY OBJECTIVE: To investigate the effect of propofol and midazolam on cardiac autonomic nervous system (CANS) activity during combined spinal-epidural anesthesia. DESIGN: Prospective, clinical study. SETTING: Operating room of a university hospital. PATIENTS: Forty ASA physical status I and II patients scheduled for knee surgery. INTERVENTION: Patients were randomized to ...
Gross Volkmar - - 2005
Regulator of G protein signaling (RGS2) deletion in mice prolongs signaling by G protein-coupled vasoconstrictor receptors and increases blood pressure. However, the exact mechanism of the increase in blood pressure is unknown. To address this question we tested autonomic nervous system function and blood pressure regulation in RGS2-deficient mice (RGS2-/-). ...
Sollers John J JJ - - 2005
Typically, blood pressure variability has been calculated by taking the simple mathematical standard deviations of a collection of discrete blood pressure (BP) measurements. Recently, spectral analytic techniques have been employed to examine beat-to-beat blood pressure variability and the underlying autonomic adjustments associated with the performance of various tasks. In the ...
Harinath Kasiganesan - - 2005
OBJECTIVE: To evaluate the role of the autonomic nervous system and adrenal system in acclimatization to cold in tropical men during short or prolonged sojourns at Antarctica. METHODS:The study was carried out on volunteers of the 18th winter over team (WOT) and 19th summer team (ST) of an Indian Antarctic ...
Sosnowski Maciej - - 2005
BACKGROUND: The scatterplot of R-R intervals has several unique features. Its numerical evaluation may produce a new useful index of global heart rate variability (HRV) from Holter recordings. METHODS: Two-hundred and ten middle-aged healthy subjects were enrolled in this study. The study was repeated the next day in 165 subjects. ...
Grimm David R - - 2005
OBJECTIVE: To determine differences in peripheral and cardiovascular autonomic function between individuals with acute musculoskeletal injury (<1 week) and healthy controls. METHODS: Autonomic cardiovascular modulation, baroreceptor sensitivity, skin conductance, and peripheral skin temperature were obtained in 6 subjects with acute musculoskeletal injury and 6 age- and sex-matched controls. Power spectral ...
Sacha Jerzy - - 2005
Heart rate variability (HRV) spectrum can be calculated from the R-R or the sequence of instantaneous heart rates (IHRs). Because these signals are reciprocal, their use in the determination of the correlation of HRV with average HR may yield opposite results. AIM: The aim of this study is to reveal ...
< 9 10 11 12 13 14 15 16 17 18 19 >