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Results 251 - 300 of 1297
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Gagne Julien J LSIIT (UMR CNRS-UdS 7005), Strasbourg University, France. - - 2009
Active cardiac stabilization has a role to play in the development of minimally invasive techniques for beating heart surgery. We propose here a new active cardiac stabilization device based on gyroscopic actuation. This system allows to compensate for heart motion in high frequencies and is fully independant and pluggable on ...
Hsin Ho-Tsung - - 2010
Heart-rate variability (HRV) analyzed by detrended fluctuation analysis (DFA), which resulted in a short-term fractal exponent - alpha, has prognostic implication in chronic phase of heart failure and survivors of myocardial infarction. We adopted DFA to study the acute-phase HRV in acute coronary syndromes (ACS) by recruiting 30 age- and ...
Agostini D - - 2008
This review focuses on myocardial [(123)I]mIBG imaging in patients with cardiomyopathy and heart failure (HF). In particular, the potential role of myocardial (123)I-mIBG scintigraphy in the prediction of potentially fatal arrhythmic events is described. A growing body of evidence supports the use of cardiac sympathetic innervation imaging, specifically using (123)I-mIBG, ...
Imrich Richard - - 2008
Stress is a well-known factor affecting cardiac contractility through the cardiac sympathetic nerves. A positive inotropic effect of the cardiac sympathetic nerves on the myocardium is reflected by pre-ejection period (PEP) shortening. Patients with Parkinson disease (PD) and neurogenic orthostatic hypotension (NOH) (PD + NOH) or with pure autonomic failure ...
Smulders N M - - 2008
Some patients with sarcoidosis can have cardiac involvement. Impairment of the cardiac sympathetic nerve activity is seen in about 50% of the sarcoidosis patients with small fiber neuropathy. In this case we present a sarcoidosis patient with small fiber neuropathy and cardiac symptoms with a cardiac sympathetic dysfunction, assessed with ...
Syed Zeeshan - - 2009
Electrocardiographic measures can facilitate the identification of patients at risk of death after acute coronary syndromes. This study evaluates a new risk metric, morphologic variability (MV), which measures beat-to-beat variability in the shape of the entire heart beat signal. This metric is analogous to heart rate variability (HRV) approaches, which ...
Ruiz Llorca C - - 2008
BACKGROUND: The incidence and prevalence of heart failure (HF) are constantly increasing. Heart failure depends on pump failure, inflammatory tracers, and the neurohormonal system. At advanced stages, the only treatment is heart transplantation (HT). We studied myocardial innervation in patients before HT. MATERIALS AND METHODS: The study included 15 patients ...
Pereira Y Martinez - - 2008
OBJECTIVES: To investigate the prognostic and diagnostic value of heart rate variability (HRV) using the vasovagal tonus index (VVTI) in dogs suffering from idiopathic dilated cardiomyopathy (DCM). METHODS: Electrocardiographic (ECG) recordings of 369 patients presented to a referral centre between 1993 and 2006 were reviewed. RESULTS: VVTI values were calculated ...
Shibata Mamoru - - 2009
We aimed to characterize the relationship between cardiac sympathetic and parasympathetic dysfunction employing cardiac (123)I-meta-iodobenzylguanidine (MIBG) uptake and other autonomic function parameters in Parkinson's disease (PD). 79 PD patients were studied. We performed (123)I-MIBG myocardial scintigraphy to assess the extent of cardiac sympathetic denervation. Electrocardiogram readings at rest and postural ...
Bai Juan - - 2008
Sympathetic denervation is frequently observed in heart disease. To investigate the linkage of sympathetic denervation and cardiac arrhythmia, we developed a rat model of chemical sympathectomy by subcutaneous injections of 6-hydroxydopamine (6-OHDA). Cardiac sympathetic innervation was visualized by means of a glyoxylic catecholaminergic histofluorescence method. Transient outward current (Ito) of ...
Ren Chongyu - - 2008
Nerve sprouting in healed myocardial infarction has been associated with increased incidences of ventricular tachyarrhythmia and sudden cardiac death. However, the underlying electrophysiological mechanisms are unclear. To investigate the linkage between nerve sprouting and potassium channel function, we developed a rat model of cardiac sympathetic nerve sprouting by chronic subcutaneous ...
Arslan Ugur - - 2008
AIMS: To study heart rate (HR) variability and HR turbulence parameters in mild-to-moderate aortic stenosis (AS) and to disclose whether any relationship exists between these parameters and echocardiographic findings. METHODS AND RESULTS: Forty-three asymptomatic patients with mild-to-moderate AS (AS group) were studied. Echocardiographic parameters and HR variability and HR turbulence ...
Hörnsten Rolf - - 2008
Reduced heart rate variability (HRV) is common in familial amyloidotic polyneuropathy (FAP), as well as cardiac arrhythmias. We examined the effects of liver transplantation (LTx) on 24-h HRV and ventricular late potentials. Twenty-one liver-transplanted FAP patients underwent Holter-ECG recordings and signal average electrocardiography recordings (SAECG) before and after LTx. Mean ...
Kilic Harun - - 2008
BACKGROUND: Heart rate turbulence (HRT) and heart rate variability (HRV) have been shown to be independent and powerful predictors of mortality in a specific group of cardiac patients. Pacing has unfavorable effects on autonomic function. Our aim is to investigate autonomic responses to atrial synchronous ventricular pacing (VDD) by evaluating ...
Mowery Nathan Teague - - 2008
BACKGROUND: A noninvasive tool reflecting intracranial hypertension (ICH) should prompt early invasive monitoring and reduce secondary injury after traumatic brain injury. We hypothesized that integer heart rate variability (HRV) may be associated with rises in intracranial pressure (ICP); changes in HRV may precede changes in ICP; and both increases in ...
Fricke Eva - - 2008
In both diabetic and nondiabetic patients, there is a loose correlation between coronary flow reserve (CFR) and sympathetic innervation in viable myocardial segments. The loose correlation implies that sympathetic innervation may be preserved even with major impairment of myocardial blood supply. In some patients, denervation is due to repetitive episodes ...
Kawashima Tomokazu - - 2008
We examined the morphology of the autonomic cardiac nervous system (ACNS) on 20 sides of 10 gibbons (Hylobatidae) of three genera, and we have inferred the evolution of the anatomy of the primate ACNS. We report the following. (1) Several trivial intraspecific and interspecific variations are present in gibbons, but ...
Nagamachi Shigeki - - 2008
(123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy is a useful tool for differentiating idiopathic Parkinson's disease (PD) from parkinsonism (PS) caused by other disorders. However, cardiac MIBG uptake is affected by various causes. Alternatively, hypoperfusion in the occipital lobe of PD is reported recently. OBJECTIVE: The objective is to clarify the correlation between ...
Langelotz Corinna - - 2008
OBJECTIVE: To determine the specific effects of working long hours in surgery and potential cardiac stress in the individual surgeon by measuring heart rate variability (HRV). DESIGN, SETTING, AND PARTICIPANTS: This prospective study measured HRV before, during, and after a 24-hour shift in a standardized resting period of 10 minutes. ...
Pomara Cristoforo - - 2009
The cardiovascular manifestations of tetanus consist of disturbances of heart rate and rhythm, blood pressure instability, arrhythmias, myocardial dysfunction and sympathetic overactivity. It was suggested that either a sudden loss of catecholamine stimulation or myocardial damage caused by the direct action of the tetanus toxin, could be involved in cardiac ...
Bär Karl-Jürgen - - 2008
BACKGROUND: Chronic alcoholism represents a risk factor for cardiac arrhythmias. One underlying mechanism is a sympathetically dominated autonomic imbalance. This is especially apparent during acute withdrawal from alcohol. Since linear analysis of heart rate variability may not be entirely adequate to detect such autonomic dysfunction in acute alcohol withdrawal, we ...
Davos Constantinos H - - 2009
BACKGROUND: Tetralogy of Fallot (ToF) patients face an increased risk of sudden cardiac death late after repair. Heart rate turbulence (HRT) indices are well-known predictors of sudden cardiac death. We aimed to estimate whether HRT is impaired in repaired ToF patients compared to healthy controls and relate those HRT parameters ...
Chen Hung Yi - - 2009
Cardiac arrhythmia is frequently detected in patients with mitral valve prolapse (MVP) and improper autonomic tone is considered the etiology. Heart rate turbulence (HRT) and heart rate variability (HRV) are methods assessed for autonomic dysfunction. To evaluate whether the number of ventricular premature contractions (VPCs) is influenced by HRT or ...
Ribeiro Antonio Luiz P - - 2009
Cardiac vagal modulation impairment is a typical feature of Chagas disease (ChD) and is correlated to antagonistic anti-M2 autoantibodies activity. In this letter, we analyze the hypothesis that, in ChD, anti-muscarinic antibody activity could simultaneously increase parasympathetic tonus (decreasing heart rate) and decrease vagal modulation over cardiac sinus node (reducing ...
Arimoto Takanori - - 2008
BACKGROUND: For assessment of cardiac sympathetic nervous activity, the conventional protocol for iodine-123-metaiodobenzylguanidine ((123)I-MIBG) imaging requires several hours. METHODS AND RESULTS: To establish whether it is possible to shorten the conventional (123)I-MIBG imaging protocol, anterior planar imaging was performed in 42 heart failure (HF) patients at 5, 15 and 180 ...
Wiklund Urban - - 2008
BACKGROUND: Cardiac autonomic dysfunction is a common complication of familial amyloidotic polyneuropathy (FAP), but cardiac arrhythmia and conduction disturbances are also common. We analyzed heart rate variability (HRV) in FAP patients using power spectrum analysis and Poincaré plot analysis. METHODS: HRV was analyzed in 24-hour ECG recordings (Holter) in 41 ...
Wehrwein Erica A - - 2008
The cardiac neuronal norepinephrine (NE) transporter (NET) in sympathetic neurons is responsible for uptake of released NE from the neuroeffector junction. The purpose of this study was to assess the chamber distribution of cardiac NET protein measured using [(3)H]nisoxetine binding in rat heart membranes and to correlate NE content to ...
Jones Christine M - - 2008
Reflex control of heart rate is frequently impaired following myocardial infarction. This is referred to as depressed baroreflex sensitivity. The aim of these experiments was to assess the function of other autonomic reflexes in dogs with depressed baroreflex sensitivity. Comparisons were made to dogs in whom baroreflex sensitivity was preserved ...
Waring W S - - 2008
PURPOSE: Antidepressant overdose may be associated with significant cardiotoxicity, and recent data have shown that acute toxic effects are associated with impaired heart rate variability. This study was designed to examine the feasibility of non-invasive heart rate variability recording in patients that present to hospital after deliberate antidepressant ingestion. METHODS: ...
Haensch C-A - - 2009
Patients with idiopathic Parkinson's disease (PD) have impaired sympathetically mediated neurocirculatory innervation. Here we analyzed the correlation between cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake, orthostatic hypotension and heart rate variability in treated patients with PD. Orthostatic hypotension (OH) as a hallmark of sympathetic neurocirculatory failure was found with a high prevalence in ...
Imrich Richard - - 2009
BACKGROUND: Diseases characterized by neurogenic orthostatic hypotension (NOH), such as Parkinson disease (PD) and pure autonomic failure (PAF), are associated with cardiac sympathetic denervation, as reflected by low myocardial concentrations of 6-[(18)F]fluorodopamine-derived radioactivity. We studied the impact of such denervation on cardiac chronotropic and inotropic function. METHODS: Cardiac inotropic function ...
Cha Yong-Mei YM Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota, USA. - - 2008
To determine the effect of cardiac resynchronization therapy (CRT) on sympathetic nervous function in heart failure (HF). Neurohormonal dysregulation and cardiac autonomic dysfunction are associated with HF and contribute to HF progression and its poor prognosis. We hypothesized that mechanical resynchronization improves cardiac sympathetic function in HF. Sixteen consecutive patients ...
de Munck J C - - 2008
Considering that there are several theoretical reasons why fMRI data is correlated to variations in heart rate, these correlations are explored using experimental resting state data. In particular, the possibility is discussed that the "default network", being a brain area that deactivates during non-specific general tasks, is a hemodynamic effect ...
Perkiömäki Juha S - - 2008
BACKGROUND: Autonomic markers, such as heart rate variability (HRV), heart rate turbulence (HRT), and baroreflex sensitivity (BRS) provide information on the risk of all-cause mortality after an acute myocardial infarction (AMI), but their value in predicting nonfatal cardiac events is not well known. METHODS: A consecutive series of 675 patients ...
Adamopoulos Dionysios - - 2008
1. Nicotine is a well studied pleiotropic agent which occurs naturally in tobacco smoke and has been largely accused for many of the adverse effects of smoking on the cardiovascular system, including autonomic imbalance, endothelial dysfunction and coronary blood flow dysregulation. 2. The acute sympathoexcitatory effects of smoking on the ...
Jönsson Peter - - 2008
Heart period variability and heart rate were studied in 15 women and 15 men while they were viewing negatively (snakes/spiders), neutrally (scenic views), and positively (cats and kittens/puppies and dogs) valenced films. Time-frequency analyses of the heart period variability power spectrum in the high frequency region (0.12-0.4 Hz), reflecting respiratory ...
Horwich Tamara B TB UCLA Medical Center, Los Angeles, CA, - - 2008
Sympathetic nervous system activation in heart failure, as indexed by elevated norepinephrine levels, higher muscle sympathetic nerve activity and reduced heart rate variability, is associated with pathologic ventricular remodeling, increased arrhythmias, sudden death, and increased mortality. Recent evidence suggests that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) therapy may provide survival ...
Del Rio Carlos L - - 2008
Parasympathetic activity during acute coronary artery occlusion (CAO) can protect against ischaemia-induced malignant arrhythmias; nonetheless, the mechanism mediating this protection remains unclear. During CAO, myocardial electrotonic uncoupling is associated with autonomically mediated immediate (i.e. type 1A) arrhythmias and can modulate pro-arrhythmic dispersion of repolarization. Therefore, the effects of acutely enhanced ...
Kamiyoshi Yuichi - - 2008
Iodine-123 metaiodobenzylguanidine (123I-MIBG) has been used to assess myocardial sympathetic nervous activity and severity of heart failure. (123)I-MIBG is also used as a potential marker of pulmonary endothelial cell function and may be related to pulmonary hypertension. Thus, we hypothesized that combined assessment of lung and heart 123I-MIBG kinetics predicts ...
Ewert T Jarred TJ Spring Arbor University, Spring Arbor, MI 49283, - - 2008
The neuropeptide galanin is elevated in the cardiac sympathetic innervation after myocardial infarction (MI). Galanin inhibits vagal transmission and may support the regeneration of sympathetic nerves, thereby contributing to the development of arrhythmia and sudden cardiac death after MI. The reason for increased galanin production in sympathetic neurons after myocardial ...
Klingenheben Thomas - - 2008
BACKGROUND: Noninvasive arrhythmia risk stratification in patients with nonischemic dilated cardiomyopathy (DCM) using autonomic markers have yielded disappointing results. Heart rate turbulence is a new method to assess cardiac autonomic function. AIM: The aim of the study was to compare the predictive value of heart rate turbulence with those of ...
Junqueira Luiz Fernando LF - - 2008
In this report, a brief history of the Valsalva (Valsalva-Weber) maneuver is outlined, followed by an explanation on the use of this approach for the evaluation of cardiac autonomic function based on underlying heart rate changes. The most important methodological and interpretative aspects of the Valsalva-Weber maneuver are critically updated, ...
Mashaly Hazem Antar - - 2008
Subarachnoid hemorrhage (SAH) serves as a good model for the study of heart-brain interactions because it is associated with both a high incidence of arrhythmia and a low prevalence of coronary heart disease. The pathophysiology of cardiac abnormalities in SAH is unsettled. Initial theories focused on sustained stimulation of cardiomyocytes ...
Chua K C - - 2008
Heart rate variability (HRV) refers to the regulation of the sinoatrial node, the natural pacemaker of the heart, by the sympathetic and parasympathetic branches of the autonomic nervous system. Heart rate variability analysis is an important tool to observe the heart's ability to respond to normal regulatory impulses that affect ...
Fellet Andrea L - - 2008
Alterations in autonomic control and myocardial nitric-oxide (NO) production are likely linked to the development and progression of heart dysfunction. By focusing on heart rate, the complexity of the actions of NO at distinct levels throughout the autonomic nervous system and its relationship with other regulators can be demonstrated. Given ...
Giannoglou George D - - 2008
Several epidemiological studies have reported that an elevated heart rate is associated with coronary atherosclerosis independently of other risk factors. In this review we explore the pathophysiologic mechanisms involved in the pro-atherosclerotic effect of elevated heart rate, apart from its association with sympathetic tone. An elevated heart rate enhances the ...
Gilman Matthew P - - 2008
Patients with heart failure or OSA (obstructive sleep apnoea) have reduced HF-HRV (high-frequency heart rate variability), indicating reduced cardiac vagal modulation, a marker of poor prognosis. CPAP (continuous positive airway pressure) abolishes OSA in patients with heart failure, but effects on daytime HF-HRV have not been determined. We hypothesized that, ...
Oikawa Keiko - - 2009
BACKGROUND: In patients with renal failure on hemodialysis cardiovascular disease is a major cause of death. It has been reported that diminished heart rate variability (HRV) relates to the unfavorable prognosis in post-infarction and/or heart failure patients. However, the prognostic value of HRV in hemodialysis patients has not been fully ...
Aso Shin-ichi - - 2009
BACKGROUND: The autoantibodies stimulate the beta1-adrenoreceptors on cardiac myocytes similar to norepinephrine, and are associated with reduced cardiac function. Iodine-123 metaiodobenzylguanidine ((123)I-MIBG) is metabolized similarly to norepinephrine. This study was undertaken to investigate the relationship between cardiac stimulation by anti-beta1-adrenoreceptor autoantibodies and myocardial sympathetic nervous activity in patients with chronic ...
Verberne Hein J - - 2008
We hypothesized that assessment of myocardial sympathetic activity with no-carrier-added (nca) (123)I-meta-iodobenzylguanidine (MIBG) compared to carrier-added (ca) (123)I-MIBG would lead to an improvement of clinical performance without major differences in radiation dosimetry. In nine healthy volunteers, 15 min and 4 h planar thoracic scintigrams and conjugate whole-body scans were performed ...
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