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Results 401 - 450 of 1331
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Kon Hisashi - - 2006
Several studies have suggested that an increased high sensitivity C-reactive protein (hsCRP) level is a strong independent predictor of increased risk for atherosclerotic cardiovascular mortality and morbidity. Reduced heart rate variability (HRV) has also been reported to predict cardiovascular events such as sudden death and myocardial infarction in apparently healthy ...
Anselme Frédéric - - 2007
Both increase in cardiac arrhythmia incidence and decrease in heart rate variability (HRV) have been described following human and experimental animal exposures to air pollutants. However, the potential causal relationship between these two factors remains unclear. Incidence of ventricular arrhythmia and HRV were evaluated during and after a 3 h ...
Lau Stephan - - 2006
Heart rate variability (HRV) is a marker of autonomous activity in the heart. An important application of HRV measures is the stratification of mortality risk after myocardial infarction. Our hypothesis is that the information entropy of HRV, a non-linear approach, is a suitable measure for this assessment. As a first ...
Sajadieh A - - 2006
OBJECTIVES: Increased C-reactive protein (CRP) and reduced heart rate variability (HRV) both indicate poor prognosis. An inverse association between HRV and CRP has been reported, suggesting an interaction between inflammatory and autonomic systems. However, the prognostic impact of this interaction has not been studied. We thus investigated the prognostic impact ...
Maestri Roberto - - 2006
We assessed the clinical correlates of a comprehensive set of non-linear heart rate variability (HRV) indices computed from 24-h Holter recordings for 200 stable chronic heart failure (CHF) patients [median age (lower quartile, upper quartile) 54 (47, 58) years, LVEF 23% (19%, 28%)]. A total of 19 non-linear indices belonging ...
Pecyna M B - - 2006
Heart rate variability (HRV) reflects periodic changes taking place in heart rhythm, which are controlled by the autonomic nervous system (ANS) and external factors. The aim of the present study was to assess the relationship between HRV and the level of intelligence using the Raven Advanced Matrices Test in 95 ...
Kristen Arnt V - - 2006
BACKGROUND: In congestive heart failure (CHF), an activation of the cardiac sympathetic nervous system results in depleted cardiac norepinephrine (NE) stores. The underlying regulatory mechanisms are discussed controversially and were investigated in the present study in CHF resulting from volume overload. METHODS AND RESULTS: Aorto-caval shunt (AVS) was performed in ...
Chen Lan S - - 2007
Sudden cardiac death (SCD) is a major cause of morbidity and mortality in patients with coronary artery diseases and myocardial infarction (MI). There is a circadian variation of the frequency of SCD. Beta-blocker therapy significantly reduces the incidence of SCD after MI. These clinical observations suggest a close association between ...
Hombach Vinzenz - - 2006
Structural heart disease, electrical instability, and increased sympathetic activity can generate a number of specific and nonspecific ECG changes and arrhythmias in patients with congestive heart failure (CHF). This review describes direct alterations of the P-QRS-T complex and ECG-derived parameters in CHF, together with the significance of cardiac arrhythmias, markers ...
Sandercock Gavin Richard H - - 2006
Classic risk factors for mortality due to chronic heart failure (CHF), such as low left ventricular ejection fraction, NYHA functional stage, and increased heart rate perform well in the prediction of death from pump failure. The prediction of sudden cardiac death (SCD) remains somewhat problematic. Numerous studies have analyzed the ...
Baumert Mathias - - 2006
Scaling analysis of heart rate time series has emerged as a useful tool for the assessment of autonomic cardiac control. We investigate the heart rate time series of ten athletes (five males and five females), by applying detrended fluctuation analysis (DFA). High resolution ECGs are recorded under standardized resting conditions ...
Delahaye Nicolas - - 2006
Familial amyloid polyneuropathy (FAP) is a rare and severe hereditary form of amyloidosis, due to the deposition of a genetic variant transthyretin essentially produced by the liver, and characterized by both sensorimotor and autonomic neuropathy. Liver transplantation (LT) is the most effective treatment to stop the progression of the disease. ...
Marthol Harald - - 2006
Sleep bruxism, an oral parafunction including teeth clenching and grinding, might be related to increased stress. To evaluate sympathetic cardiac activity in bruxism patients, we monitored cardiac autonomic modulation using spectral analysis of heart rate variability and compared results to those of age-matched healthy volunteers. In bruxism patients, sympathetic cardiac ...
Cotter P A - - 2006
We compared electrocardiographic signals in hatchery-reared, non-spinally-transected, immature rainbow trout (Oncorhynchus mykiss Walbaum) under clove oil (25 ppm), tricaine methanesulfonate (tricaine, 60 ppm), and benzocaine (108 ppm) general anesthesia (35 min, 14 degrees C). For all 3 anesthetics, the mean heart rate (HR) and QRS amplitude did not differ, and ...
Diaz Alberto - - 2006
In mammalian ventricles including humans, it is recognized that parasympathetic ganglia innervate the heart. Little is known about the location and function of right ventricular parasympathetic nerves in humans. We hypothesized that in humans: (1) there are parasympathetic ganglia that supply the right ventricle that can be stimulated via an ...
Morris John A JA - - 2006
BACKGROUND: Measurements of a patient's physiologic reserve (age, injury severity, admission lactic acidosis, transfusion requirements, and coagulopathy) reflect robustness of response to surgical insult. We have previously shown that cardiac uncoupling (reduced heart rate variability, HRV) in the first 24 hours after injury correlates with mortality and autonomic nervous system ...
Bauer Axel - - 2006
BACKGROUND: Decreased vagal activity after myocardial infarction results in reduced heart-rate variability and increased risk of death. To distinguish between vagal and sympathetic factors that affect heart-rate variability, we used a signal-processing algorithm to separately characterise deceleration and acceleration of heart rate. We postulated that diminished deceleration-related modulation of heart ...
Ugur Bakiye - - 2006
The purpose of this study was to use estimates of corrected QT dispersion (QTcd) and heart rate variability (HRV) to assess the effects of sevoflurane, an inhalation agent used frequently in clinical practice, on autonomic cardiac function. This study was conducted prospectively and in a blind manner on 20 women ...
Alter Peter - - 2006
BACKGROUND: Decreased heart rate variability (HRV) has been shown to reflect disturbances of the autonomic nervous system that is related to increased cardiovascular mortality. Most studies investigated HRV in patients with systolic left ventricular dysfunction due to remote myocardial infarction or dilated cardiomyopathy. To date, only few data are available ...
Burr Robert L RL Department of Biobehavioral Nursing and Health Systems, School of Nursing, University of Washington, Seattle 98195-7266, USA. - - 2006
Heart rate variability (HRV) indices based on 24-hr electrocardiograph recordings have been used in clinical research studies to assess the aggregate activity of the autonomic nervous system. Although 24-hr HRV is generally considered noninvasive, use in research protocols typically involves considerable data collection and processing expenses and substantial participant burden. ...
Meyer M - - 2006
The dynamics of heartbeat interval fluctuations were studied in awake unrestrained mice following intracerebroventricular application of the neuropeptide corticotropin-releasing factor (CRF). The cardiac time series derived from telemetric ECG monitoring were analyzed by non-parametric techniques of nonlinear signal processing: delay-vector variance (DVV) analysis, higher-order variability (HOV) analysis, empirical mode decomposition ...
Papaioannou Vasilios E - - 2006
PURPOSE: To investigate longitudinally over time heart rate dynamics and relation with mortality and organ dysfunction alterations in patients admitted to a multidisciplinary intensive care unit. METHODS: Data from 53 patients were used, with heart rate recorded from monitors and analyzed on a daily basis (every morning) for 600 seconds ...
Mitsui Jun - - 2006
Decreased cardiac uptake in (123)I-metaiodobenzylguanidine (MIBG) scintigraphy has been adopted as one of the most reliable diagnostic tests for Parkinson disease (PD) in Japan. To investigate the morphological basis for this finding, we performed a detailed neuropathological study of the cardiac sympathetic nervous system of a 71-year-old autopsy-proven PD patient, ...
Alvarenga Marlies E - - 2006
BACKGROUND: The risk of adverse clinical cardiac events is increased in patients with panic disorder (PD). We evaluated possible mechanistic links between PD and heart disease. We estimated cardiac vagal activity from heart rate variability (HRV) measurements and quantified sympathetic nervous system (SNS) activity using plasma noradrenaline tracer kinetics methodology. ...
Sassi Roberto - - 2006
Analysing the Holter recordings collected at baseline during the European Myocardial Infarction Amiodarone Trial (EMIAT), we evaluate the possibility of using alpha, the slope of the power spectrum of heart rate variability signals (HRV) in the vicinity of f = 0, for postinfarction risk stratification. We found no relevant difference ...
Thakre Tushar P - - 2006
BACKGROUND: Heart rate variability (HRV) is known to be impaired in patients with congestive heart failure (CHF). Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance ...
Godleski John J - - 2006
This article focuses on responses to ambient particles by the heart. Available data from human studies and animal studies are reviewed in an attempt to find a common understanding in the findings. The pathophysiologic mechanisms responsible for these health effects are likely to be complex, and it is highly probable ...
Finkelstein Jason S - - 2006
Although autonomic dysfunction is a common manifestation of Guillain-Barré syndrome, cardiovascular involvement in this setting has rarely been reported in the literature. We describe a case of reversible left ventricular systolic dysfunction in a 60-year-old man with Guillain-Barré syndrome. Our patient had no history or signs of cardiac dysfunction on ...
Wu G Q GQ Dept. of Mech. & Eng. Sci., Fudan Univ., Shanghai. - - 2006
Circadian rhythms of heart rate variability have been widely studied in recent years. However, most previous reports described such rhythms in terms of normalized units of the low- and high-frequency (LF and HF) spectral components. In this study, we analyzed circadian rhythms of spectral components in absolute units and found ...
Signorini M G MG Dept. of Bioeng., Politecnico di Milano, Milan, - - 2006
The purpose of this work is to characterize the heart rate variability (HRV) of patients affected by congestive heart failure (CHF) and to find out the main difference between this pathological condition and the physiological state. Parameters adopted in this work are: the detrended fluctuation analysis (DFA) and the Higuchi ...
Lanza G A - - 2006
OBJECTIVES: To assess the prognostic value of ventricular arrhythmias (VA) and heart rate variability (HRV) in patients with unstable angina. DESIGN: Multicentre prospective study. SETTING: 17 cardiological centres in Italy. PATIENTS: 543 consecutive patients with unstable angina and preserved left ventricular function (ejection fraction >or=40%) enrolled in the SPAI (Stratificazione ...
Kreusser Michael M - - 2006
An impairment of cardiac norepinephrine reuptake through the neuronal norepinephrine transporter promotes depletion of cardiac norepinephrine stores and local cardiac sympathetic activation in heart failure. Nerve growth factor regulates differentiation and survival of adult sympathetic cells and is decreased in failing hearts. We hypothesized that injection of nerve growth factor ...
Zang Wei-Jin - - 2005
Autonomic nervous system plays an important role in the regulation of mammalian heart, and it is divided into the sympathetic and parasympathetic (vagal) subsystems. The parasympathetic (vagal) control of the atria involves modulation of chronotropic, dromotropic and inotropic activities, but the role of the parasympathetic innervation of the ventricles is ...
Sugiura Masato - - 2006
BACKGROUND: The status of cardiac sympathetic nerve activity in patients with diastolic heart failure has not been fully understood. 123-I-metaiodobenzylguanidine cardiac images are valuable for evaluating cardiac sympathetic nerve activity. METHODS: We obtained 123-I-metaiodobenzylguanidine cardiac images from 34 consecutive patients with moderate heart failure and an ejection fraction of > ...
Adamson Philip B - - 2005
Continuous measurement of spontaneous heart rate variability is now possible from permanently implanted devices and may contain information useful in the chronic management of patients with congestive heart failure. Since heart rate variability semi-quantifies autonomic control of the heart, changes noted from continuous measurement provide insight into cardiac control system ...
Cohen-Solal Alain - - 2005
Carvedilol is a beta-blocking agent with antioxidant properties that has been shown to improve survival in chronic heart failure (CHF). Previous open-label studies have suggested that its use may have positive effects on the abnormalities of cardiac sympathetic innervation integrity and functioning. The present study aimed to test the hypothesis ...
Liang Chang-Seng - - 2006
Cardiac sympathetic transmitter stores are reduced in the failing heart. In this study, we proposed to investigate whether the reduction of cardiac sympathetic neurotransmitters was associated with increased interstitial norepinephrine (NE) and reactive oxygen species in congestive heart failure (CHF), using a microdialysis technique and salicylate to detect .OH generation. ...
Longin Elke - - 2006
BACKGROUND: Heart rate variability (HRV) reveals information on the functional state of the autonomic nervous system (ANS) in neonates. During severe illness, heart rate variability is impaired. AIM: This study was initiated to measure the changes in HRV in neonates during extracorporeal membrane oxygenation (ECMO) and recovery from severe respiratory ...
Gurses Dolunay - - 2005
OBJECTIVE: Cardiac complication is one of the major causes of death in patients with thalassaemia major. Heart rate variability is a non-invasive index of neuronal modulation of heart rate. In this study, autonomic functions of the heart in a preclinical stage of heart disease were evaluated in 48 thalassaemic patients ...
Matsui T - - 2005
The impaired balance of the low-frequency/high-frequency ratio obtained from spectral components of RR intervals can be a diagnostic test for sepsis. In addition, it is known that a reduction of heart rate variability (HRV) is useful in identifying septic patients at risk of the development of multiple organ dysfunction syndrome ...
Suzuki Masahiko - - 2006
BACKGROUND: Iodine-123-labeled metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy has been used to evaluate cardiac sympathetic denervation in Lewy body disease (LBD) including Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Patients with LBD had marked reductions in cardiac MIBG accumulation, indicative of severe impairment of the cardiac sympathetic nervous systems. However, ...
Chan H L - - 2005
Spectral analysis of heart rate variability provides a probe to assess the function of the sympathetic and parasympathetic nervous systems. Time-frequency analysis of heart rate variability is useful for investigating autonomic nervous function in patients with syncope or non-sustained ventricular tachycardia, or in anaesthesia, etc. In this paper, we developed ...
Garet Martin - - 2005
PURPOSE: Heart rate variability (HRV) indices are powerful independent prognostic factors of cardiovascular events and all cause mortality in patients with chronic heart failure (CHF). This study evaluates the influence of lifestyle on HRV in CHF patients. METHODS: Thirty-nine CHF patients (33 men, ischemic/dilated cardiomyopathy (18/21), 52.4 +/- 11.2 yr, ...
Anastasiou-Nana Maria I - - 2005
Autonomic nervous system dysfunction is common in congestive heart failure (CHF) and is believed to predispose patients to an increased risk of death. This study aimed to assess the prognostic significance of heart rate variability (HRV) measurements in conjunction with scintigraphic imaging using metaiodobenzylguanidine (MIBG) labeled with iodine-123 (I-123-MIBG), which ...
Kubo Toshihiko - - 2005
We have documented a pre-junctional beta-2 adrenoceptor mediated reduction in cardiac norepinephrine spillover (CNES) in heart failure patients receiving chronic beta-blockade. Our present objective was to ascertain the consequence of this decrease for vagal heart rate (HR) regulation by determining CNES, arterial baroreflex sensitivity for HR (BRS) and arterial baroreflex ...
Guzzetti Stefano - - 2005
BACKGROUND: Sympathetic and parasympathetic systems are considered the principal rapidly reacting systems that control heart rate. METHODS AND RESULTS: We propose a symbolic analysis series to quantify the prevalence of sympathetic or parasympathetic cardiac modulation. This analysis decomposes the heart rate variability series in patterns lasting 3 beats and classifies ...
Burri Haran - - 2006
INTRODUCTION: Studies evaluating changes in HRV preceding the onset of ventricular arrhythmias using conventional techniques have shown inconsistent results. Time-frequency analysis of HRV is traditionally performed using short-term Fourier transform (STFT). Wavelet transform (WT) may however be better suited for analyzing non-stationary signals such as heart rate recordings. METHODS AND ...
Stöllberger Claudia - - 2006
The findings of Kawasaki et al. [T. Kawasaki, A. Azuma, T. Taniguchi, et al. Heart rate variability in adult patients with isolated left ventricular noncompaction. Int J Cardiol 2005;99:147-150.] raise the following questions: why was dilated cardiomyopathy not investigated? How many of the patients with left ventricular hypertrabeculation/noncompaction (LVHT) showed ...
Gehi Anil A Zena and Michael A. Wiener Cardiovascular Institute, Mount Sinai School of Medicine, New York, New York, - - 2005
We examined the association between anemia (hemoglobin < or =12 g/dl) and 6 indexes of heart rate variability (HRV) as measured by 24-hour ambulatory electrocardiography in a cross-sectional study of 874 outpatients who had stable coronary heart disease. Of 90 participants who had anemia, 29% to 41% had low HRV, ...
Danson Edward J - - 2005
Nitric oxide (NO) is a potent modulator of cardiac and vascular regulation. Its role in cardiac-autonomic neural signaling has received much attention over the last decade because of the ability of NO to alter cardiac sympathovagal balance to favor more anti-arrhythmic states. Complexity and controversy have arisen, however, because of ...
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