Search Results
Results 501 - 550 of 1808
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Radaelli Alberto - - 2006
OBJECTIVES: The intention of this study was to test the hypothesis that, in heart failure patients, dietary supplementation of polyunsaturated fatty acids (PUFA) enhances arterial baroreceptor control of the cardiovascular system. BACKGROUND: Administration of PUFA reduces the risk of life-threatening arrhythmias in patients surviving myocardial infarction. This might result from ...
Farah Vera M A - - 2006
Studies evaluated the role of the autonomic nervous system in the cardiovascular response to stress using radiotelemetric blood pressure (BP) recording coupled with autoregressive spectral analysis. Conscious male C57/BL6 mice with carotid arterial telemetric catheters were exposed to acute episodes of shaker stress before and after administration of cholinergic, beta1-adrenergic ...
Bär Karl-Jürgen - - 2006
BACKGROUND: Many symptoms of alcohol withdrawal (AW) such as tachycardia or elevated blood pressure might be explained by increased peripheral and central adrenergic activity. In contrast to many neurochemical studies of sympathetic activation during AW, only very few studies investigated autonomic balance using neurophysiological methods. METHODS: We investigated heart rate ...
Kim Young-Kug - - 2006
Compromised cardiac autonomic modulation can produce cardiovascular disturbances. We investigated whether combined deep and superficial cervical plexus (CP) blockade for carotid endarterectomy (CEA) produces changes in autonomic cardiovascular regulation. To estimate alterations in cardiovascular autonomic control before and after combined CP blockade in 22 patients undergoing CEA, the heart rate ...
Yakhou Leïla - - 2006
Carotid artery stenting (CAS) has been introduced as an alternative to carotid endarterectomy (CEA) for the treatment of carotid artery stenosis. Both techniques seem to be associated with postoperative hemodynamic lability. Both may induce baroreceptor dysfunction, possibly leading to transient impairment of cardiovascular autonomic activity and resulting in hemodynamic instability. ...
Serra X - - 2007
This paper describes the effect of high pressure (400MPa and 600MPa) applied to frozen hams at early stages of the dry-cured ham process: green hams (GH) and hams at the end of the resting stage (ERS), on some physicochemical parameters and on antioxidant and proteolytic enzyme activities in the final ...
Tewari Hem Kumar - - 2006
PURPOSE: This case-control study was conducted to evaluate autonomic function activity and reactivity in patients with central serous chorioretinopathy (CSCR), because stress and type A personality, known risk factors, are also related to autonomic nervous system activity. METHODS: Patients with CSCR were selected from the outpatient department and medical retina ...
Moriguchi Koichi - - 2006
The relation between changes in blood pressure and changes in autonomic activity over a very short period of time has not been reported thus far. To examine this relation, we here introduced a new method of power spectrum analysis with wavelet transformation, which has very fine time resolution and is ...
Skrapari Ioanna - - 2006
Arterial baroreceptors play an important role in the short-term regulation of arterial pressure, by reflex chronotropic effect on the heart and by reflex regulation of sympathetic outflow. Baroreflex sensitivity (BRS) represents an index of arterial baroreceptors function. Several methods of measuring BRS are available nowadays. Different factors influence BRS in ...
Valance D - - 2007
This study investigated whether genetic selection on a divergent behavioural trait of fearfulness (tonic immobility duration) was related to changes in the nervous control of the heart. Quail selected for either long or short tonic immobility (LTI or STI, respectively) duration was compared with an unselected control line (CTI). The ...
Iellamo Ferdinando - - 2006
Endothelial function is impaired in first-degree relatives (FDRs) of patients with type 2 diabetes. Many states characterized by endothelial dysfunction are associated with increased cardiovascular sympathetic outflow. In this study, we investigated endothelial and autonomic nervous system (ANS) functioning in FDRs and tested the hypothesis that in basal condition, impaired ...
Westerhof Berend E - - 2006
Postural stress requires immediate autonomic nervous action to maintain blood pressure. We determined time-domain cardiac baroreflex sensitivity (BRS) and time delay (tau) between systolic blood pressure and interbeat interval variations during stepwise changes in the angle of vertical body axis (alpha). The assumption was that with increasing postural stress, BRS ...
Marc A. Rosen, Raymond ...
The effect of increasing reheat pressure on the exergy efficiency of a coal-fired steam power plant is investigated. The results show that although the irreversibility rate associated with heat transfer in the steam generator decreases as reheat pressure increases, the overall-plant exergy efficiency decreases, mainly owing to the relatively large ...
Rademaker Miriam T - - 2006
AIMS: To investigate the haemodynamic, hormonal, and renal effects of peripheral urocortin 3 (Ucn3) administration for the first time in either normal health or heart failure (HF). METHODS AND RESULTS: Eight sheep received incremental intravenous boli of Ucn3 (10, 50, and 100 microg at 2-h intervals) before (normal) and during ...
Campbell Hamish A - - 2006
Autonomic control of heart rate variability and the central location of vagal preganglionic neurones (VPN) were examined in the rattlesnake (Crotalus durissus terrificus), in order to determine whether respiratory sinus arrhythmia (RSA) occurred in a similar manner to that described for mammals. Resting ECG signals were recorded in undisturbed snakes ...
Gadegbeku Crystal A - - 2006
OBJECTIVE AND DESIGN: Plasma lipids enhance alpha1-adrenoceptor pressor sensitivity, impair baroreflex function, and correlate with increased blood pressure. This clinical study was designed to determine whether the enhanced alpha1-pressor sensitivity induced by acute hyperlipidemia is primarily mediated by increased vascular alpha1 responsiveness, reduced baroreflex sensitivity (BRS) or both. METHOD: Regional ...
Schumacher Autumn M - - 2006
Cardiac variability can be assessed from two perspectives: beat-to-beat performance and continuous performance during the cardiac cycle. Linear analysis techniques assess cardiac variability by measuring the physical attributes of a signal, whereas nonlinear techniques evaluate signal dynamics. This study sought to determine if recurrence quantification analysis (RQA), a nonlinear technique, ...
Dias Fernando A L - - 2006
Although it has been suggested that in cardiac muscle the phosphorylation level of myosin regulatory light chain (RLC) correlates with frequency of stimulation, its significance in the modulation of the force-frequency and pressure-frequency relationships remains unclear. We examined the role of RLC phosphorylation on the force-frequency relation (papillary muscles), the ...
Paul-Labrador Maura - - 2006
BACKGROUND: The metabolic syndrome is thought to be a contributor to coronary heart disease (CHD), and components of the syndrome have been identified as possible therapeutic targets. Previous data implicate neurohumoral activation related to psychosocial stress as a contributor to the metabolic syndrome. The aim of this study was to ...
Polson Jaimie W - - 2006
BACKGROUND: Coarctation of the aorta (CoA) is associated with hypertension and abnormalities of blood pressure control, which persist after late repair. Assumptions that neonatal repair would prevent development of blood pressure abnormalities have not been supported by recent data. We hypothesized that early pathological adjustment of autonomic cardiovascular function may ...
Shibata Shigeki - - 2006
Cardiovascular variability reflects autonomic regulation of blood pressure (BP) and heart rate (HR). However, systolic BP (SBP) variability also may be induced by fluctuations in stroke volume through left ventricular end-diastolic pressure (LVEDP) variability via dynamic ventricular-arterial coupling during respiration. We hypothesized that dynamic ventricular-arterial coupling is modulated by changes ...
Wirch Jennifer L - - 2006
The primary objective of this study was to develop a cold pressor test (CPT) protocol to evaluate cardiac autonomic function. Secondary objectives were to assess CPT protocol reliability and to examine gender differences in response to orthostatic stress and the CPT. Healthy, normotensive men and women (n = 12 per ...
Gipson C L - - 2006
Changes in cardiac output may occur during insufflation for laparoscopic procedures. However, there are limited data regarding its potential effects on cerebral oxygenation. Cerebral oxygenation (ScO(2)), end tidal CO(2), heart rate, blood pressure and oxygen saturation by pulse oximetry were recorded every 5 minutes prior to insufflation, during insufflation and ...
Diaz Tulio - - 2006
The arterial baroreflex is important for beat-to-beat arterial pressure control and its sensitivity has predictive value for clinical outcomes in a myriad of cardiovascular conditions. Given this, researchers have sought approaches for baroreflex assessment that are not invasive and easily obtained. These techniques have exploited the beat-by-beat parallel changes in ...
Monahan Kevin D - - 2006
Baroreflex function is impaired in patients with obstructive sleep apnoea. We tested the hypothesis that short-term exposure to repetitive hypoxic apnoeas (RHA) produces prolonged impairment in baroreflex function. Baroreflex function was determined using the modified Oxford technique in 14 subjects (26 +/- 1 years). Baroreflex sensitivity (BRS) was quantified from ...
Beckers Frank - - 2006
1. The present study assesses the effects of autonomic blockade (alpha- and beta-adrenoceptor and cholinergic) on cardiovascular function studied by heart rate variability (HRV), blood pressure variability (BPV) and baroreflex sensitivity in rats using non-linear dynamics. Little is known about the influence of pharmacological autonomic nervous system interventions on non-linear ...
Singh D - - 2006
The background to heart rate variability (HRV) and blood pressure variability (BPV), and their determinants and physiological correlates, remain obscure. The impact of age must be taken into account if HRV and BPV are used for predictive purposes in clinical settings. Healthy subjects show wide inter-individual variation in their heart ...
Huang C-J - - 2006
BACKGROUND: Peri-operative hymodynamic instability is one of the major concerns for anesthesiologists when performing general anesthesia for individuals with autonomic dysfunction. The purpose of this study was to examine the potential usage of pre-operative measurement of heart rate variability (HRV) in identifying which individuals, with or without diabetes, may be ...
Solem Kristian - - 2006
Clinical techniques for early detection of acute hypotension during conventional hemodialysis treatment are lacking, even though intradialytic hypotension is the most common acute complication. In this article, intradialytic hypotension is identified by means of signal analysis of data recorded at two clinics. The database consists of 30 treatments with concurrently ...
Oginosawa Yasushi - - 2006
INTRODUCTION: Conventional baroreceptor-heart rate (HR) reflex sensitivity cannot be examined in chronotropically incompetent patients or in pacemaker recipients. However, cardiac baroreceptor reflex sensitivity (BRS)-stroke volume (SV), which is closely and linearly correlated with BRS-HR, may be an alternative in that population. The aim of this study was to compare the ...
Fox Justin M - - 2006
Pressure-volume analysis has provided critical insight into ventricular mechanics, and it has elucidated the underlying mechanisms of heart failure (HF). Renewed interest in ventriculovascular coupling, the interaction of the left ventricle and the arterial system, has developed from recent investigations focusing on the importance of heart rate control in systolic ...
Atlasz Tamás - - 2006
The aim of the present study was to test whether the electromagnetic field emitted by standard GSM mobile phones results in changes in heart rate (HR) and heart rate variability (HRV) of 35 healthy young male and female subjects. Two parallel signals, electrocardiogram and infrared surface plethysmogram were recorded and ...
Fujiwara Y - - 2006
Heart rate variability (HRV) was investigated using a new technique for time series analysis combining the maximum entropy method and non-linear least squares method -- the 'MemCalc method' -- in patients undergoing general anesthesia with sevoflurane and fentanyl for elective surgery. As the occurrence of junctional rhythm coincided with the ...
Chen Jay - - 2006
The purpose of this manuscript is to review the current literature regarding the role of the autonomic nervous system (ANS) in atrial fibrillation (AF). We will be reviewing its effect on initiation, maintenance, and termination of AF, with emphasis on the role of baroreflex gain (BRG) and autonomic reflexes in ...
Mager Donald E - - 2006
Dietary restriction (DR) has been shown to increase life span, delay or prevent age-associated diseases, and improve functional and metabolic cardiovascular risk factors in rodents and other species. To investigate the effects of DR on beat-to-beat heart rate and diastolic blood pressure variability (HRV and DPV) in male Sprague-Dawley rats, ...
Haensch Carl-Albrecht - - 2006
Extrasystoles occur in normal subjects but are significant more frequently (16.25% vs. 55%; chi(2) = 19.3; P < 0.001) seen in Parkinson's disease (PD) patients. The extrasystolic decreases in stroke volume and systolic pressure activate sympathetic vasomotor innervation and lead to a blood pressure increase for a few heartbeats. The ...
Deguchi K - - 2006
Although heart rate (HR) responses to hyperventilation (HV) have been used as a cardiovascular autonomic function test, autonomic involvement during HV remains uncertain. To clarify the relationship between autonomic activity and cardiovascular changes during HV, we compared cardiovascular responses during HV among subjects with different autonomic function, namely 16 patients ...
Norozi Kambiz - - 2006
Heart failure (HF) is a major problem in the long-term follow-up of adults with congenital heart disease (CHD) after cardiac surgery. The purpose of this study was to evaluate risk factors for HF in patients with CHD. N-terminal-pro-brain natriuretic peptide and maximal oxygen uptake (VO2max) were measured in 345 consecutive ...
Siu Chung-Wah - - 2006
Ventricular tachyarrhythmias may occur during intravenous arsenic trioxide (As2O3). This has not happened during oral As2O3. Sixteen patients were studied by electrocardiography and 24-hour Holter monitoring at baseline, during and after oral As2O3 (As2O3-ON, As2O3-OFF). QT and corrected QT (QTc) were significantly longer during As2O3-ON than in As2O3-OFF, but QT ...
van Vliet J A - - 2006
While facial autonomic signs are prominent during cluster headache (CH) attacks, cardiovascular autonomic changes have been described in few CH patients. Cardiovascular autonomic function tests (AFT) can be used to assess general autonomic function in CH patients in different stages of the disease. We aimed to assess whether general autonomic ...
Vallejo Maite - - 2006
Particulate air pollution has been related with cardiopulmonary morbidity and mortality. Recent studies have shown that an increase in particulate matter (PM)(2.5) ambient concentrations was associated with a decrease in heart rate variability (HRV) in the elderly with cardiovascular conditions, which could increase the risk of death. In order to ...
Tsuchiya S - - 2006
BACKGROUND AND OBJECTIVE: Thiopental has been reported to reduce sympathetic tone, however, it is not clear whether change in heart rate variability is associated with depth of anaesthesia. The purpose of the present study was to evaluate changes in heart rate variability at different depths of hypnosis during induction of ...
Ogawa Yojiro - - 2006
STUDY OBJECTIVE: To evaluate the different effects on autonomic circulatory control during volatile induction/maintenance of anesthesia (VIMA) vs total intravenous anesthesia (TIVA). DESIGN: Prospective study. SETTING: Operating theater of a university hospital. PATIENTS: Twenty patients, with American Society of Anesthesiologists physical status of I or II, were randomly allocated into ...
Connes Philippe - - 2006
Sickle cell trait (SCT) is a genetic disease affecting the synthesis of normal haemoglobin (Hb) and marked by the heterozygous presence of HbA and HbS. Some studies have suggested that SCT carriers might be prone to vascular alterations, cardiac ischaemia and arrhythmias leading, in some subjects, to sudden death. It ...
Hanss Robert - - 2006
BACKGROUND: Hypotension due to vasodilatation after spinal anesthesia (SA) may be harmful. Heart rate variability, an indirect measure of autonomic control, may predict hypotension. METHODS: One hundred patients were studied. Retrospectively, heart rate variability was analyzed in 30 patients, classified depending on the lowest systolic blood pressure (SBP) after SA. ...
Khurana Ramesh K - - 2006
Application of cold to the face evokes potent bradycardia and a pressor response, similar to the diving reflex. However, the role of the baroreceptors in this response is unclear. Ten healthy controls and two patients with baroreflex impairment were recruited. A cold face test (CFT) was induced by the application ...
Milutinović Sanja - - 2006
The role of neurally born acetylcholine in the central modulation of cardiovascular short-term variability was assessed using a pharmacological probe physostigmine, a cholinesterase inhibitor that can act centrally also. Experiments were performed in instrumented conscious rats. Equidistant sampling at 20 Hz of systolic arterial pressure (SAP), diastolic arterial pressure (DAP) ...
Lai C J - - 2006
Long-term exposure to intermittent hypoxia (IH), such as that occurring in association with sleep apnea, may result in systemic hypertension; however, the time course changes in arterial pressure, autonomic functions, and baroreflex sensitivity are still unclear. We investigated the changes in cardiovascular neural regulations during the development of chronic IH-induced ...
Wiegerinck Rob F - - 2006
BACKGROUND: Patients with heart failure (HF) have an increased QRS duration, usually attributed to decreased conduction velocity (CV) due to ionic remodeling but which may alternatively result from increased heart size or cellular uncoupling. We investigated the relationship between QRS width, heart size, intercellular coupling, and CV in a rabbit ...
Fu Chin-Hua - - 2006
The incidence of cardiovascular disease is higher in postmenopausal women than in premenopausal women. We hypothesized that long-term vegetarian diets might modulate cardiovascular autonomic functions measured by frequency-domain techniques in healthy postmenopausal women. A total of 35 healthy vegetarians (mean age +/- SEM 55.0 +/- 1.3 years) who had been ...
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