Search Results
Results 451 - 500 of 1861
< 5 6 7 8 9 10 11 12 13 14 15 >
Karas Maria - - 2008
The effect of age on autonomic nervous system was assessed at rest and while standing using systolic blood pressure (SBP) and diastolic blood pressure (DBP), heart rate, and power spectral analysis of the time duration between 2 consecutive R waves of an electrocardiogram (RR) interval variability, as well as on ...
Jaja S I - - 2008
Autonomic function following change in posture with or without vitamin C supplementation was studied in ten (10) sickle cell anemia (SCA) and twelve (12) non-sickle cell anemia (NSCA) subjects. Arterial blood pressure and electrocardiographic measurements were taken in the supine position on a couch 80cm high and immediately on assumption ...
Sala-Mercado Javier A - - 2008
Dynamic cardiac baroreflex responses are frequently investigated by analyzing the spontaneous reciprocal changes in arterial pressure and heart rate (HR). However, whether the spontaneous baroreflex-induced changes in HR translate into changes in cardiac output (CO) is unknown. In addition, this linkage between changes in HR and changes in CO may ...
Jan Yih-Kuen - - 2008
OBJECTIVES: To provide insight into the physiologic mechanisms associated with alternating pressure, using wavelet analysis of skin blood flow (SBF) oscillations, and to determine whether the application of alternating pressure induces myogenic responses, thereby enhancing SBF as compared with constant loading. DESIGN: Repeated-measures design. SETTING: University research laboratory. PARTICIPANTS: Healthy, ...
Smith Stephen Matthew - - 2008
OBJECTIVE: To compare estimates of cardiac baroreceptor sensitivity (BRS) obtained by the Finapres device and from the direct measurement of arterial blood pressure (ABP) values from the ascending aorta, using both spectral analysis and sequence analysis. DESIGN: A cohort study of 45 coronary artery disease patients undergoing routine percutaneous coronary ...
Haegele-Link S - - 2008
Different components of the autonomic nervous system may be affected by different disorders to varying degrees. The aim of this study is to report first experiences with a new device (FAN(R), Schwarzer, Germany) which measures heart rate variability (HRV), sympathetic skin responses (SSR) and the pulse wave transit time (PTT). ...
Cai Fin Z J - - 2008
INTRODUCTION: The aim of this study was to compare cardiovascular autonomic nervous system function in patients with primary Sjögren's syndrome (pSS) with that in control individuals, and to correlate the findings with autonomic symptoms and the presence of exocrine secretory dysfunction. METHODS: Twenty-seven female patients with pSS and 25 control ...
Sesay Musa - - 2008
BACKGROUND: We studied sympathovagal activity using real-time heart rate variability (HRV) and determined its relationship with plasma catecholamines to characterize short-term cardioregulatory mechanisms during laparoscopic adrenal pheochromocytoma surgery. METHODS: We recruited 20 patients with pheochromocytoma (Group P) and 20 with incidentaloma (Group I). HRV, systolic blood pressure and heart rate ...
Wyller Vegard Bruun - - 2008
BACKGROUND: Hemodynamic abnormalities have been documented in the chronic fatigue syndrome (CFS), indicating functional disturbances of the autonomic nervous system responsible for cardiovascular regulation. The aim of this study was to investigate autonomic heart rate control during mild orthostatic stress in adolescents with CFS. METHODS: A total of 14 CFS ...
Mourot Laurent - - 2008
BACKGROUND: Moderately cold head-out water immersion stimulates both baro- and cold-receptors, and triggers complex and contradictory effects on the cardiovascular system and its autonomic nervous control. OBJECTIVES: To assess the effects of water immersion and cold on cardiovascular status and related autonomic nervous activity. METHODS: Hemodynamic variables and indexes of ...
Theofilogiannakos Efstratios K - - 2008
OBJECTIVE: Fatal arrhythmias are a common cause of death in chronic obstructive pulmonary disease (COPD). Two major hypotheses for arrhythmogenesis in COPD have been proposed: arrhythmias are a consequence of hypoxaemia, hypercapnia or (tissue localised) acid-base disturbances, or arrhythmias are the result of the autonomic neuropathy that characterises COPD. Our ...
Lavinio Andrea A Institute of Anaesthesiology and Intensive Care Medicine, Ospedale Civile, Pzz.le Spedali Civili, 1, 25100 Brescia, Italy. - - 2008
The autonomic nervous system exerts tonic control on cerebral vessels, which in turn determine the autoregulation of cerebral blood flow. We hypothesize that the impairment of cerebral autoregulation following traumatic brain injury might be related to the acute failure of the autonomic system. This prospective, observational study included patients with ...
Abe Makoto M Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan. - - 2008
A human watching a swaying image displayed on a wide-field display or screen sometimes suffers from visually-induced motion sickness (VIMS) that causes symptoms related to the autonomic nervous system such as nausea, vomiting, and dizziness. Previous studies indicated that the maximum cross-correlation coefficient (rho(max)) between blood pressure and heart rate, ...
Papaioannou Vasilios - - 2008
PURPOSE: The purpose of the study was to investigate longitudinally over time heart rate (HR) and blood pressure variability and baroreflex sensitivity in acute brain injury patients and relate them with the severity of neurologic dysfunction and outcome. METHODS: Data from 20 brain injured patients due to multiple causes and ...
Galuszka Jan - - 2007
AIMS: The purpose of the study was to demonstrate autonomic nervous system (ANS) changes associated with treatment in hypertensive patients and utilization of these measurements in practice. METHODS: Hypertensive patients were examined before the start of treatment and after blood pressure compensation. The telemetric system VarCor PF 5 was used ...
Strudwick Mark W - - 2007
INTRODUCTION: Point injection as a therapeutic technique is well documented, but its physiological effects have not been formally compared with traditional acupuncture. One aim of this study was to compare the effects of the two techniques at one acupuncture point, as a step towards understanding the mode of action of ...
Hamaad Ali - - 2007
Several beta blocking drugs (BB) reduce mortality in systolic heart failure (LVSD). We have compared the initial response to introduction of carvedilol and bisoprolol during the standard dose titration protocols for each drug. Approximately 31 unselected patients with stable LVSD were randomised to either carvedilol or bisoprolol measuring blood pressure, ...
Claydon Victoria E - - 2008
Spinal cord injury (SCI) has profound effects on cardiovascular autonomic function due to injury to descending autonomic pathways, and cardiovascular diseases are the leading causes of morbidity and mortality after SCI. Evaluation of cardiovascular autonomic dysfunction after SCI and appraisal of simple noninvasive autonomic assessments that are clinically meaningful would ...
Stemper B - - 2008
OBJECTIVE: To evaluate the impact of vagus nerve stimulation (VNS) on heart rate and blood pressure (BP) modulation in epilepsy patients. MATERIAL AND METHODS: Twenty-one epilepsy patients with VNS were tested during on (60 s) and off (5 min) phases. We monitored BP, RR intervals (RRI) and respiration. Spectral analysis ...
Chen Xiaoxiao - - 2008
Heart rate (HR) power spectral indexes are limited as measures of the cardiac autonomic nervous systems (CANS) in that they neither offer an effective marker of the beta-sympathetic nervous system (SNS) due to its overlap with the parasympathetic nervous system (PNS) in the low-frequency (LF) band nor afford specific measures ...
Laude Dominique - - 2008
Short-term blood pressure (BP) variability is limited by the arterial baroreflex. Methods for measuring the spontaneous baroreflex sensitivity (BRS) aim to quantify the gain of the transfer function between BP and pulse interval (PI) or the slope of the linear relationship between parallel BP and PI changes. These frequency-domain (spectral) ...
Chen Xiaoxiao - - 2008
We previously developed a mathematical analysis technique for estimating the static gain values of the arterial total peripheral resistance (TPR) baroreflex (G(A)) and the cardiopulmonary TPR baroreflex (G(C)) from small, spontaneous beat-to-beat fluctuations in arterial blood pressure, cardiac output, and stroke volume. Here, we extended the mathematical analysis so as ...
Huang Chih-Cheng - - 2007
The baroreflex maintains a stable blood pressure (BP) by dynamically adjusting heart rate (vagal component) and total peripheral resistance (adrenergic component). Vagal baroreflex sensitivity (BRS-v) is widely used but no methodology existed to quantitate adrenergic baroreflex sensitivity (BRS-a) until we developed the indices of BP recovery time (PRT) and BRS-a. ...
Hanss R - - 2007
BACKGROUND: To investigate if changes in low-to-high frequency ratio (LF/HF), low frequency (LF) and high frequency (HF) heart rate variability reflect autonomic regulation during spinal anaesthesia (SA) in pregnant women scheduled for elective Caesarean section. METHODS: Prospective clinical trial. Systolic blood pressure (SBP) and heart rate variability were analysed at ...
Catz A - - 2007
OBJECTIVE: Study hemodynamic responses to cold application to the foot (CAF) to explore the autonomic cardiovascular control by the spinal cord. DESIGN: Controlled experimental study. Hemodynamic variables were measured or calculated for 13 healthy subjects, 10 patients with traumatic T4-T6 paraplegia, and 11 patients with traumatic C4-C7 tetraplegia. Subjects were ...
Vorluni L - - 2008
AIM: This study evaluated the influence of muscle mechanical afferent stimulation on the integrated arterial baroreflex control of the sinus node during dynamic exercise. METHODS: Systolic blood pressure (SBP) and pulse interval (PI) were measured continuously and non-invasively in 15 subjects at rest and during passive cycling. The arterial baroreflex ...
Umeno Katsumi K System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, - - 2008
Relationships between smell sensation and autonomic changes have been studied extensively. However, the possibility that odorants may also act on the lung and lower airway remains unknown. The present results provide the first evidence that the lung and lower airway exert an inhibitory influence on the cardiovascular system in response ...
Maser Raelene E - - 2008
BACKGROUND: Sleep-disordered breathing (SDB) is an independent risk factor for cardiovascular morbidity. Dysfunction of the cardiovascular autonomic nervous system may be a potential mechanism whereby SDB is linked to cardiovascular disease. Repetitive sympathetic activation during apneic episodes may impair cardiovascular reflex function, and increased sympathetic activity can stimulate renin release. ...
Oka H - - 2007
OBJECTIVE: To examine the relation between the results of cardiac (123)I-meta-iodobenzylguanidine (MIBG) scintigraphy and cardiovascular autonomic function in Lewy body disease (LBD). METHODS: The subjects were 66 patients with LBD, 44 of whom had Parkinson disease (PD), 10 PD with dementia (PDD), and 12 dementia with Lewy bodies (DLB); 20 ...
Zhu Heng - - 2007
To better understand the mechanisms of tear drainage, the mechanical properties of porcine canaliculus were measured in compression mode while submerged in isotonic fluid by using a dynamic mechanical analyzer. The storage modulus (E') for the porcine canaliculus is about 3 kPa at 1 Hz and increases to about 5 ...
de Souza Neto Edmundo Pereira - - 2007
Heart beat rate and blood pressure, together with baroreflex sensitivity, have become important tools in assessing cardiac autonomic system control and in studying sympathovagal balance. These analyses are usually performed thanks to spectral indices computed from standard spectral analysis techniques. However, standard spectral analysis and its corresponding rigid band-pass filter ...
Birch Anthony A - - 2007
OBJECTIVES: The objective of this work was to test the hypothesis that the Finapres underestimates blood pressure during sympathetic peripheral vasoconstriction. METHODS: Measurements were made simultaneously with two Finapres devices and one radial artery tonometer during the onset of periodic lower body negative pressure in healthy volunteers. The Finapres is ...
Duschek Stefan - - 2007
The cardiac baroreflex constitutes an important mechanism mediating autonomic control of heart activity. Its function can be quantified by applying sequence analysis based on continuous recordings of blood pressure and heart rate. In this study, several indices derived from this method were compared regarding their suitability to estimate baroreflex function ...
Verheyden B - - 2007
AIM: Astronauts commonly return from space with altered short-term cardiovascular dynamics and blunted baroreflex sensitivity. Although many studies have addressed this issue, post-flight effects on the dynamic circulatory control remain incompletely understood. It is not clear how long the cardiovascular system needs to recover from spaceflight as most post-flight investigations ...
Passino Claudio - - 2007
OBJECTIVE: To assess the effects of acute exposure to simulated high altitude on baroreflex control of mean cerebral blood flow velocity (MCFV). PATIENTS AND METHODS: We compared beat-to-beat changes in RR interval, arterial blood pressure, mean MCFV (by transcranial Doppler velocimetry in the middle cerebral artery), end-tidal CO2, oxygen saturation ...
Fujiwara Y - - 2007
BACKGROUND: The objective of this study was to determine whether pre-operative heart rate variability (HRV) estimated using the newly developed MemCalc method predicts hypotension after spinal anaesthesia (SA). METHOD: Fifty-two patients with American Society of Anesthesiologists physical status I or II, aged 38-84 years, scheduled to undergo elective transurethral surgery ...
Tanaka Kazuhiko - - 2007
Heart failure (HF) commonly results in atrial fibrillation (AF) and fibrosis, but how the distribution of fibrosis impacts AF dynamics has not been studied. HF was induced in sheep by ventricular tachypacing (220 bpm, 6 to 7 weeks). Optical mapping (Di-4-ANEPPS, 300 frames/sec) of the posterior left atrial (PLA) endocardium ...
Tanakaya Machiko - - 2007
Postprandial hypotension is an important hemodynamic abnormality in diabetes mellitus, but few reports are available on the relationship between autonomic dysfunction and postprandial hypotension. Ten diabetic patients and 10 healthy volunteers were recruited for this study. Postural blood pressure and heart rate changes were measured before lunch, and then the ...
Kurosawa Tomoko - - 2007
An association between ambient air pollution and reduced cardiac autonomic function assessed by heart rate variability (HRV) mainly in elderly persons has been suggested by a number of epidemiological studies, but the link between the HRV and pulmonary function in humans remains unknown although such air pollution should primarily affect ...
Mourot Laurent - - 2007
The present study was aimed at investigating the autonomic nervous system influences on the fractal organization of human heart rate during sympathovagal interactions, with special emphasize on the short-term fractal organization in heart rate variability (HRV), as assessed by the scaling exponent (alpha(1)) of the detrended fluctuation analysis. Linear and ...
Studinger Péter - - 2007
According to conventional wisdom, hysteresis in cardiac vagal baroreflex function exhibits a specific pattern: pressure falls are associated with longer heart periods and a smaller linear gain. A similar pattern occurs in the pressure-diameter relationship of barosensory vessels, and therefore it has been suggested that baroreflex hysteresis derives solely from ...
Mandl Thomas - - 2007
OBJECTIVE: Exocrine function always is and autonomic nervous function may be impaired in primary Sjögren's syndrome (pSS). Since autonomic nervous signaling is a prerequisite for exocrine secretion we wanted to assess autonomic nervous function in pSS and relate it to diagnostic measures of exocrine function. METHODS: Autonomic nervous function was ...
Jin Yu - - 2008
To evaluate whether neuropathic pain affects autonomic nervous activities, we investigated daily change in cardiovascular parameters and plasma norepinephrine (NE) in free-moving rats after chronic constriction injury (CCI) on the sciatic nerve. Arterial blood pressure (BP), heart rate (HR), and the power spectrum of pulse interval variability were analyzed. Daily ...
Biaggioni Italo - - 2007
Patients with autonomic failure provide a unique opportunity to study the role of sympathetic function on the regulation of blood volume. These patients have a reversal of the normal diurnal variation in urine output and have twice as much natriuresis during the night. Autonomic failure patients are also unable to ...
Zöllei Eva - - 2007
The aim of this study was to assess the influence of breathing pattern on the reproducibility of the most commonly used heart rate and blood pressure variability parameters and baroreflex indices. 5-5 min ECG and blood pressure recordings were made and repeated for 10 healthy volunteers in supine rest on ...
Dabisch Paul A - - 2007
Several studies in conscious animals have reported parasympathetic dysfunction in the eyes following exposure to cholinesterase inhibitors. Given the similarities between the autonomic innervation in the eye and the heart, it is possible that parasympathetic dysfunction could also occur in the heart. Therefore, the present study assessed time domain indices ...
Melo R C - - 2008
BACKGROUND: Evaluation of non-pharmacological therapies that improve autonomic control of the heart rate in older subjects has a clinical significance, because reduced heart rate variability (HRV) can be associated with higher cardiovascular morbidity and mortality rates. OBJECTIVE: To investigate if strength training improves cardiac autonomic control in healthy older men. ...
Bissonnette John M - - 2007
Methyl-CpG-binding protein 2 is a transcription factor that is involved in gene silencing. It is mutated in the majority of cases of Rett syndrome. This X-linked neurodevelopmental disorder is reported to involve abnormalities in autonomic cardiovascular regulation. As an initial step in understanding the basis for these abnormalities we have ...
Yilmaz Ugur - - 2007
PURPOSE: We investigated the role of the autonomic nervous system in the chronic pelvic pain syndrome by studying blood pressure changes, power spectral analysis of heart rate variability, and hand and foot sympathetic skin responses in men with the chronic pelvic pain syndrome and healthy controls. MATERIALS AND METHODS: We ...
Diedrich André - - 2007
BACKGROUND: Children with Congenital Central Hypoventilation Syndrome (CCHS) typically present as newborns with alveolar hypoventilation. With the advent of genetic testing, parents of affected children and other unrelated adults, all heterozygous for the disease-defining PHOX2B polyalanine expansion mutation with the 20/25 genotype, are being identified in adulthood. Though children with ...
< 5 6 7 8 9 10 11 12 13 14 15 >