Search Results
Results 201 - 250 of 1316
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Maestri Roberto - - 2010
Despite a well-established prognostic value in cardiac patients, HRV (heart rate variability) indexes have been used little in the clinical setting. Poor reliability of the measurements might be a possible explanation for this. In the present study, we assessed the reliability of short-term HRV indexes in post-MI (myocardial infarction) patients. ...
Karmakar C K - - 2009
The asymmetry in heart rate variability is a visibly obvious phenomenon in the Poincaré plot of normal sinus rhythm. It shows the unevenness in the distribution of points above and below the line of identity, which indicates instantaneous changes in the beat to beat heart rate. The major limitation of ...
Ghebremedhin Estifanos - - 2009
Clinical and autopsy studies have consistently reported cardiac sympathetic dysfunction in the left ventricular wall in patients with Parkinson's disease (PD). Whether the nerve fibers of the cardiac conduction system or the atrial walls are equally affected in this disease process has not yet been well documented. Therefore, the aim ...
Chen Hung Yi - - 2009
BACKGROUND: Heart rate turbulence (HRT) has recently been introduced as a noninvasive tool for studying autonomic dysfunction. It presented short time fluctuation of sinus cycle length following single ventricular premature contraction (VPC). However, HRT parameters may be influenced by different factors. This study aimed to evaluate the possible influence of ...
Zhang Youhua - - 2009
BACKGROUND: Autonomic dysfunction, characterized by sympathetic activation and vagal withdrawal, contributes to the progression of heart failure (HF). Although the therapeutic benefits of sympathetic inhibition with beta-blockers in HF are clear, the role of increased vagal tone in this setting has been less studied. We have investigated the impact of ...
Kobayashi Seiju - - 2009
Recent studies have demonstrated the usefulness of 123I-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy for the diagnosis of dementia with Lewy bodies (DLB). In this study, we investigated the relationship between decreased cardiac MIBG uptake and clinical symptoms in DLB. Thirty-six patients with probable DLB and six normal controls underwent MIBG scintigraphy. We ...
Almoznino-Sarafian Dorit - - 2009
BACKGROUND: Low heart rate variability (HRV) was found in various medical conditions including heart failure and acute myocardial infarction. Decreased HRV in these conditions predicted poor prognosis. METHODS: HRV was estimated in 133 unselected inpatients with relevant clinical bedside conditions by non-linear analysis derived from chaos theory, which calculates the ...
Surges R - - 2009
Reduced heart rate variability (HRV) may predispose to sudden unexpected death in epilepsy (SUDEP). We ascertained whether HRV predicts SUDEP in chronic epilepsy using a case-control design and investigated parameters of inter-ictal HRV in 14 patients (7 had died from SUDEP). No HRV parameter was associated with SUDEP. Thus, although ...
Netravathi M - - 2009
OBJECTIVES: Comparative evaluation of cardiac dysautonomia in spinocerebellar ataxias (SCA) and idiopathic sporadic ataxias (IA) not fulfilling the criteria of multiple system atrophy. MATERIAL AND METHODS: Cardiac autonomic functions were evaluated in 14 SCA (SCA1 = 6, SCA2 = 5 and SCA3 = 3) and 10 IA patients, comparable for ...
Schwartz Peter J - - 2009
This article reviews the background and rationale that have led to the first in-man study of the effects of direct chronic vagal stimulation for the management of heart failure. Following a brief discussion of the concept of "autonomic imbalance," the focus shifts to the wealth of pathophysiologic information gathered over ...
Flotats A - - 2009
Diabetes mellitus is a risk factor for cardiovascular morbidity and death. Cardiac autonomic diabetic neuropathy (CADN) is a common and serious complication of diabetes mellitus, which consists of damage to the autonomic nerve fibres that innervate the heart and blood vessels, resulting in alterations in heart rate control and vascular ...
Verrier Richard L - - 2009
Heart rate is a precisely regulated variable, which plays a critical role in health and disease. Numerous epidemiologic studies and large post-myocardial infarction trials have provided evidence that elevated resting heart rate is an independent risk factor for cardiac mortality. This body of knowledge has prompted the development and evaluation ...
Shehab Abdullah - - 2009
The aim was to compare measures of heart rate variability (HRV) in patients who presented with non-cardiac vascular episodes with age- and gender-matched control patients. One hundred and fifty patients, randomly selected from a cohort of 522 subjects, were enrolled in a screening study. Of these, 256 were identified to ...
Piccirillo Gianfranco G Dipartimento di Scienze dell'Invecchiamento, Università degli Studi di Roma La Sapienza, Rome, Italy. - - 2009
This study sought to find out more about the relationship between sympathetic and vagal nerve activity and the cardiac repolarization in a canine model of pacing-induced tachycardia congestive heart failure (CHF). The QT variability index (QTVI), a noninvasive marker of temporal cardiac repolarization dispersion, is among the risk factors for ...
Haensch Carl-Albrecht - - 2010
BACKGROUND: Postural orthostatic tachycardia syndrome (POTS) is a disorder of orthostatic intolerance characterised by excessive tachycardia of unknown aetiology. Whether this condition involves abnormal cardiac sympathetic innervation or function remains elusive. Meta-iodobenzylguanidine (MIBG) resembles guanethidine and is a pharmacologically inactive analogue of norepinephrine, which is similarly metabolised in noradrenergic neurons. ...
Koutelou Maria - - 2009
OBJECTIVE: We aimed at evaluating the combined use of heart rate variability (HRV), baroreflex sensitivity (BRS), and MIBG imaging in the risk stratification for sudden cardiac death (SCD) of patients with mild to moderate heart failure. METHODS: Twenty-five patients (17 male and 8 female, mean age 63 +/- 5 years, ...
Han Ying - - 2009
The current study was designed to determine whether castration with or without testosterone replacement resulted in changes in cardiac sympathetic nerve activity in rats with heart failure induced by isoproterenol. At eight weeks post-castration, dysfunction of the cardiac sympathetic nerve system was aggravated as indicated by elevated plasma norepinephrine, reduced ...
Galluzzi Samantha - - 2009
BACKGROUND: Cardiac autonomic dysfunction has been associated with cognitive impairment, but the underlying pathogenesis is complex and cerebral white matter lesions (WMLs) might be implicated. METHODS: Time and frequency heart rate variability (HRV) and visual rating of WMLs were carried out in 42 patients with mild cognitive impairment. RESULTS: After ...
Turpeinen Anu K - - 2009
BACKGROUND: Idiopathic dilated cardiomyopathy (IDC) is characterized by sympathetic nervous overactivity, inflammation and neurohumoral activation; however, their interrelationships are poorly understood. METHODS AND RESULTS: We studied 99 patients with IDC (age 54 +/- 1 years, left ventricular ejection fraction (EF) 40 +/- 1%, maximum oxygen uptake (VO(2)max) 20 +/- 1 ...
Rutjanaprom Wasarut - - 2009
BACKGROUND: Cardiac failure remains the major cause of death in beta-thalassemia major (TM). Reduced heart rate variability (HRV) is associated with a higher risk of arrhythmias after myocardial infarction and heart failure. We evaluated HRV in TM patients and its relationship with hemodynamics and echocardiographic parameters during a 6-month follow-up. ...
Kosaka Toshimitsu - - 2009
Left ventricular (LV) diastolic dysfunction is related to increased cardiac sympathetic activity. We investigated the effect of cilnidipine, an L/N-type calcium channel blocker, on LV diastolic function and cardiac sympathetic activity in patients with hypertensive heart disease (HHD) using radionuclide myocardial imaging. Thirty-two frame electrocardiography (ECG) -gated (99m)Tc-sestamibi (MIBI) myocardial ...
Buccelletti E - - 2009
BACKGROUND: Heart rate, measured as beat-to-beat intervals, is not constant and varies in time. This property is known as heart rate variability (HRV) and it has been investigated in several diseases, including myocardial infarction (MI). The main hypothesis is that HRV embed some physiological processes that are characteristics of regulatory ...
Heinz Lara - - 2009
BACKGROUND: Sudden cardiac death in athletes is more common than in the general population. Routine screening procedures are performed to identify competitors at risk. A new Holter-based parameter analyzes variation of the ventricular repolarization (TVar). The aim of this study was to evaluate differences in electrocardiogram (ECG), Echo, and Holter ...
Valentini Mariaconsuelo - - 2009
In both physiologic and pathological conditions, instantaneous heart rate value is the result of a rather complex interplay. It constantly varies under the influence of a number of factors: nonmodifiable and modifiable ones. Pharmacologic blockade with beta-adrenergic antagonists and/or with parasympathetic antagonists such as atropine have permitted the identification of ...
Richardson T - - 2009
BACKGROUND: Cardiac autonomic dysfunction post ST-segment elevation myocardial infarction (STEMI) has been linked to an excess risk of premature cardiovascular morbidity and mortality above those with normal autonomic function post-STEMI. AIM: The aim of this study was to evaluate the effect of acute ingestion of coffee on autonomic function and ...
Maestri Roberto - - 2009
Despite a well established prognostic value in cardiac patients, heart rate variability (HRV) indexes have been little used in the clinical setting. Poor reliability of the measurements might be a possible explanation. In this study we assessed the reliability of short-term HRV indexes in post myocardial infarction (MI) patients. We ...
Adams Jenny - - 2009
OBJECTIVES: To determine whether a controlled breathing programme increases heart rate variability following an acute myocardial infarction and/or coronary artery bypass graft surgery. RATIONALE: Heart rate variability is reduced following a myocardial infarction, and low heart rate variability is associated with a high mortality risk. By changing tidal volume and ...
Baumert Mathias - - 2009
Changes in measures of heart rate variability (HRV) have been associated with an increased risk for sudden cardiac death. The mechanisms underlying this association are not known. The objective of this study was to assess the relationship between the amount of norepinephrine (NE) released from the cardiac sympathetic terminals and ...
Buchner Teodor - - 2009
Human heart rate is moderated by the autonomous nervous system acting predominantly through the sinus node (the main cardiac physiological pacemaker). One of the dominant factors that determine the heart rate in physiological conditions is its coupling with the respiratory rhythm. Using the language of stochastic processes, we analyzed both ...
Glass Leon - - 2009
In June 2008, the editors of Chaos decided to institute a new section to appear from time to time that addresses timely and controversial topics related to nonlinear science. The first of these deals with the dynamical characterization of human heart rate variability. We asked authors to respond to the ...
McGlone Laura - - 2009
We undertook a study to describe changes in heart rate variability (HRV) postoperatively in children undergoing cardiac bypass surgery for congenital heart disease (CHD). HRV was recorded for a 1-h period preoperatively and a 24-h period postoperatively in 20 children with CHD. We found a highly significant reduction in HRV ...
Wernli Gwenaelle - - 2009
Myocardial infarction induces sympathetic axon sprouting adjacent to the necrotic region, and this has been implicated in the etiology of arrhythmias resulting in sudden cardiac death. Previous studies show that nerve growth factor (NGF) is essential for enhanced post-infarct sympathetic sprouting, but the cell types necessary to supply this neurotrophic ...
Folino Antonio F - - 2009
AIMS: Epidemiological studies show that peak exposure to air pollution is associated with increased morbidity and mortality from cardiovascular events. Panel and controlled exposure studies show that particulate matter (PM) may influence the parasympathetic regulation of the heart. The aim of this study was to concurrently measure individual exposure to ...
Wahab A - - 2009
To study the effect of Heart Rate Variability (HRV) and QT dispersion (QTd) in patients presenting with acute ST elevation myocardial infarction (STEMI). 100 patients of Acute myocardial infarction (AMI) were evaluated by history and examination. Electrocardiogram (ECG) and Holter monitoring was done in all patients. HRV, QTd, Standard Deviation ...
Neumann Serina A - - 2009
Previous evidence suggests that the dual-specific A kinase-anchoring protein 2 functional polymorphism (AKAP10 (A/G) I646V) influences heart rate (HR) and heart rate variability (HRV) in mice and humans (N=122) with cardiovascular disease. Here, we asked whether this AKAP10 variant predicts HR and HRV in a large sample of healthy humans. ...
Tobaldini Eleonora E Department of Clinical Sciences, Internal Medicine II, L. Sacco Hospital, University of Milan, Via G.B. Grassi 74, Milan, - - 2009
Congestive heart failure (CHF) is associated with neurohumoral activation. Only very few studies have examined the progression of autonomic dysfunction in CHF in humans and scanty data are available in animal models of CHF. This study was performed to assess the changes in cardiac autonomic modulation during the progression of ...
Huikuri Heikki V - - 2009
Heart rate variability (HRV) has been conventionally analysed with time- and frequency-domain methods, which measure the overall magnitude of RR interval fluctuations around its mean value or the magnitude of fluctuations in some predetermined frequencies. Analysis of heart rate dynamics by novel methods, such as heart rate turbulence after ventricular ...
Goldstein David S - - 2009
There is substantial interest in identifying biomarkers to detect early Parkinson disease (PD). Cardiac noradrenergic denervation and attenuated baroreflex-cardiovagal function occur in de novo PD, but whether these abnormalities can precede PD has been unknown. Here we report the case of a patient who had profoundly decreased left ventricular myocardial ...
Grassi Guido - - 2009
Congestive heart failure (CHF) is characterized not only by profound abnormalities in the haemodynamic profile but also by changes in sympathetic cardiovascular function. These neurogenic abnormalities are important features of the disease that can affect the prognosis of CHF and to become a target for therapeutic intervention. This article addresses ...
Hamaad Ali - - 2009
BACKGROUND: Acute coronary syndromes (ACS) are characterized by abnormal heart-rate variability (HRV) and biomarkers of endothelial damage and thrombosis. HYPOTHESIS: We hypothesized an association between these factors in patients with ACS. METHODS: We studied 99 patients with ACS measuring HRV and plasma markers of endothelial damage/dysfunction (von Willebrand factor, vWF) ...
Werdan Karl - - 2009
In sepsis, systemic inflammatory response syndrome (SIRS), and multiorgan dysfunction syndrome (MODS), a severe prognostically relevant cardiac autonomic dysfunction exists, as manifested by a strong attenuation of sympathetically and vagally mediated heart rate variability (HRV). The mechanisms underlying this attenuation are not limited to the nervous system. They also include ...
Moak Jeffrey P - - 2009
BACKGROUND: Power spectral analysis of heart rate variability (HRV) has been used to indicate cardiac autonomic function. High-frequency power relates to respiratory sinus arrhythmia and therefore to parasympathetic cardiovagal tone; however, the relationship of low-frequency (LF) power to cardiac sympathetic innervation and function has been controversial. Alternatively, LF power might ...
Grigorean Valentin Titus - - 2009
The aim of this article is to analyze cardiac dysfunctions occurring after spinal cord injury (SCI). Cardiac dysfunctions are common complications following SCI. Cardiovascular disturbances are the leading causes of morbidity and mortality in both acute and chronic stages of SCI. We reviewed epidemiology of cardiac disturbances after SCI, and ...
Lujan Heidi L - - 2009
Midthoracic spinal cord injury is associated with ventricular arrhythmias that are mediated, in part, by enhanced cardiac sympathetic activity. Furthermore, it is well known that sympathetic neurons have a lifelong requirement for nerve growth factor (NGF). NGF is a neurotrophin that supports the survival and differentiation of sympathetic neurons and ...
Nanjo Shuji - - 2009
BACKGROUND: Because increased sympathetic nervous activity (SNA) in patients with dilated cardiomyopathy (DCM) associated with sleep breathing disorder (SBD) is known to deteriorate the prognosis of cardiac failure, (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy was used as the investigative tool in the present study. METHODS AND RESULTS: The study group comprised 53 ...
Björkander Inge - - 2009
BACKGROUND: Heart rate variability (HRV) reflects the balance between cardiac parasympathetic and sympathetic autonomic influences. Reduced HRV has adverse prognostic implications. The time course for changes in HRV over prolonged periods of time and the influence of an acute coronary event on HRV are not well established. METHODS: Heart rate ...
Ieda Masaki - - 2009
The heart is abundantly innervated, and the nervous system precisely controls the function of this organ. The density of cardiac innervation is altered in diseased hearts, which can lead to unbalanced neural activation and lethal arrhythmia. For example, diabetic sensory neuropathy causes silent myocardial ischemia, characterized by loss of pain ...
Chen Grace P - - 2009
Congestive heart failure increasingly contributes to the overall morbidity and mortality associated with cardiovascular disease. Although significant advances in therapies allow patients to feel better and have improved functional status and survival, not all patients respond equally to these therapies. Moreover, for any given level of left ventricular systolic dysfunction, ...
Syed Zeeshan - - 2009
Unstable conduction system bifurcations following ischemia and infarction are associated with variations in the electrocardiographic activity spanning the heart beat. In this paper, we investigate a spectral energy measure of morphologic differences (SE-MD) that quantifies aspects of these changes. Our measure uses a dynamic time-warping approach to compute the time-aligned ...
Smilde Tom D J - - 2009
BACKGROUND: In contrast to patients with moderate to severe chronic heart failure (CHF), data regarding long-term outcome in patients with mild CHF are scarce. We examined the place of Holter monitoring to study the prognostic value of ventricular arrhythmias and heart rate variability (HRV) in patients with mild to moderate ...
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