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Results 401 - 450 of 1620
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Tang M - - 2005
The discrimination of ECG signals using nonlinear dynamic parameters is of crucial importance in the cardiac disease therapy and chaos control for arrhythmia defibrillation in the cardiac system. However, the discrimination results of previous studies using features such as maximal Lyapunov exponent (&#955;<inf>max</inf>) and correlation dimension (D<inf>2</inf>) alone are somewhat ...
Krause B J - - 2005
AIM: Ventricular arrhythmias have been shown to originate in the myocardial peri-infarct region due to irregular heterotopic conduction. Hypoperfused but viable myocardium is often localised in those areas and may be involved in the pathogenesis of arrhythmias. We tested the hypothesis that these myocardial perfusion/metabolism mismatches (MM) are significantly associated ...
Monzon Jorge - - 2005
This paper presents an adaptive-network-based fuzzy inference system (ANFIS) as a cardiac beat detector, able to classify normal vs. premature ventricular contractions. We used records from the MIT Arrhythmia Database and in-vivo records from cardiac voluntary patients to train and test our system. The system identifies premature ventricular contractions (PVC) ...
Chen-Scarabelli Carol - - 2005
Supraventricular arrhythmias are the most wide-spread group of arrhythmias and affect all age groups. Atrial fibrillation is the most common arrhythmic disorder and is even more prevalent among the elderly. Due to their prevalence, it is imperative for the clinician to be informed about these arrhythmias and treatment considerations. This ...
Chan H L - - 2005
Heartbeat detection is very important for retrieving the vital signs of heart functions. The morphologies and inter-beat intervals of heartbeats can reveal the condition of heart contraction. In this paper, we developed a heartbeat information integration scheme to deal with the information yielded by the energy thresholding and template match ...
Amar David - - 2004
Rapid atrial arrhythmias affect close to one million elderly Americans who undergo cardiac or non-cardiac operations annually and have been associated with prolonged hospital stays. In contrast, bradyarrhythmias or ventricular arrhythmias severe enough to require treatment occur in less than 1% of patients who undergo all types of surgery, including ...
Lobel Robert M - - 2004
Both ventricular and atrial arrhythmias are commonly encountered in patients with ventricular dysfunction. In fact, roughly half of the deaths occurring in patients with ventricular dysfunction are caused by ventricular arrhythmias. Atrial arrhythmias in this patient population compromise left ventricular filling and if uncontrolled can exacerbate (and in some cases ...
Kozlovski Valery I - - 2004
We tested antiarrhythmic and endothelial action of novel decahydroquinoline derivatives. Antiarrhythmic activity was analyzed using models of aconitine-, calcium chloride-, and adrenaline-induced arrhythmias in rats. Potency to induce nitric oxide (NO)-dependent coronary vasodilation was assessed in isolated guinea pig heart perfused according to Langendorff technique. Among 15 novel decahydroquinoline derivatives ...
Elming Hanne - - 2004
The prevalence of arrhythmia in the population is increasing as more people survive for longer with cardiovascular disease. It was once thought that antiarrhythmic therapy could save life, however, it is now evident that antiarrhythmic therapy should be administrated with the purpose of symptomatic relief. Since many patients experience a ...
Gilmour Robert F RF - - 2004
Cardiac arrhythmias are a leading cause of morbidity and mortality in many developed countries. Despite intensive investigation, the cellular mechanisms for most cardiac arrhythmias have not been clearly established. As a consequence, drug therapy for most forms of atrial and ventricular arrhythmias remains largely empirical and ineffective, leading to the ...
Kozák Milan - - 2004
The endothelins are peptides with vasoconstricting and growth-promoting properties. Endothelin-1 (ET-1) is known with its direct positive inotropic and chronotropic effects on isolated heart and with growth effects. The aim of this pilot study was to investigate the frequency distribution of the common polymorphism of the ET-1 gene and its ...
Unlü R Erkin - - 2004
Phenol preparations are used in dermatology and plastic surgery for the treatment of acne and during chemical face peeling. At this institution, phenol peeling is used in addition to mechanical dermabrasion for the elimination of subclinical premalignant lesions of patients having xeroderma pigmentosum. As the phenol peel is performed, most ...
Danik Stephan B - - 2004
Connexin43 (Cx43), the predominant ventricular gap junction protein, is critical for maintaining normal cardiac electrical conduction, and its absence in the mouse heart results in sudden arrhythmic death. The mechanisms linking reduced Cx43 abundance in the heart and inducibility of malignant ventricular arrhythmias have yet to be established. In this ...
Critchley Hugo D - - 2005
Patients with specific neurological, psychiatric or cardiovascular conditions are at enhanced risk of cardiac arrhythmia and sudden death. The neurogenic mechanisms are poorly understood. However, in many cases, stress may precipitate cardiac arrhythmia and sudden death in vulnerable patients, presumably via centrally driven autonomic nervous system responses. From a cardiological ...
Adamson Philip B - - 2004
OBJECTIVES: This study examined the hypothesis that the sympathomimetic activity of ephedrine increases the risk of lethal arrhythmias. BACKGROUND: The sympathomimetic amine, ephedrine, is used to augment physical performance and as a weight loss aid, but little is known about the cardiovascular consequences in individuals with ischemic heart disease. METHODS: ...
DiDonato M - - 2004
Ventricular arrhythmias cause ~50% of deaths in remodeled ventricles after myocardial infarction, and the Multicenter Automatic Defibrillator Implantation Trial (MADIT II) showed that the Implantable Cardioverter Defibrillator (ICD) saved lives in high risk coronary patients with advanced left ventricular dysfunction. We studied 382 patients with remodeled hearts by preoperative Ventricular ...
Knotzer Hans - - 2004
PURPOSE OF REVIEW: To review the medical literature on new-onset arrhythmias after cardiac bypass surgery in adults, focusing on the most recent advances on this topic. RECENT FINDINGS: Main attention is focused on possible predictors and prevention of postoperative atrial fibrillation, because this arrhythmia is the most common type encountered ...
Singh Steven N. - - 2004
Both supraventricular and ventricular arrhythmias are associated with increased mortality and morbidity. Numerous antiarrhythmics have been developed in an attempt to decrease the frequency of these arrhythmias, hoping to improve survival and improve quality of life. Antiarrhythmic agents are a diverse group of drugs that affect various cardiac ionic channels ...
Wellens Hein J J - - 2004
During the last 40 years, much progress has been made in our understanding and management of cardiac arrhythmias. A major step in the late 1960s was to combine programmed electrical stimulation of the heart with intracardiac activation recording. This allowed: 1) localization of the site of the block in the ...
Belhassen Bernard - - 2004
The case of a 28-year-old man with recurrent syncope and multiple documented episodes of idiopathic ventricular fibrillation is reported. Recurrent syncope suggesting a self-terminating ventricular tachyarrhythmia occurred after 1 month of amiodarone therapy, and ventricular fibrillation was inducible at electrophysiologic study. After addition of quinidine, no significant ventricular arrhythmias could ...
Biffi Alessandro - - 2004
OBJECTIVES: The purpose of this research was to evaluate the impact of athletic training and, in particular, physical deconditioning, on frequent and/or complex ventricular tachyarrhythmias assessed by 24-h ambulatory (Holter) electrocardiogram (ECG). BACKGROUND: Sudden deaths in athletes are usually mediated by ventricular tachyarrhythmias. METHODS: Twenty-four hour ambulatory ECGs were recorded ...
Lee Astin K Y - - 2004
Many cardiovascular events, including ventricular arrhythmias, display diurnal variability with a morning peak, and a less pronounced afternoon peak. Since the advent of multiprogrammable implantable cardioverter-defibrillators (ICDs), it has been possible to analyse ventricular tachyarrhythmic events. This study aims to evaluate the circadian pattern of ventricular tachycardias in patients treated ...
Benza Raymond L - - 2004
BACKGROUND: Arrhythmias are common in chronic heart failure and affect outcomes. The incidence and significance of new arrhythmias in acute heart failure, however, are largely unknown. METHODS AND RESULTS: The Outcomes of a Prospective Trial of Intravenous Milrinone for Exacerbations study randomized 949 patients with decompensated heart failure to receive ...
Kitano Yukari - - 2004
BACKGROUND: Ventricular arrhythmias have been shown to be the major cause of sudden cardiac death in hemodialysis (HD) patients. We investigated whether angiographic coronary stenosis was responsible for the induction of ventricular arrhythmias in HD patients. METHODS: HD patients (n = 150) showing ischemic signs in exercise electrocardiography or echocardiography ...
gillen, kelly
This project analyzes several of the parameters involved in the use of radiofrequency ablation (RFA) in the treatment of cardiac arrhythmia. Arrhythmia is an irregular beating of the heart that can be caused by improperly timed contractions within the heart, which can, in certain circumstances, be corrected by ablating tissue. ...
Wasson Sanjeev - - 2004
Electrical remodeling involves alterations in the electrophysiologic milieu of myocardium in various disease states, such as ventricular hypertrophy, heart failure, atrial tachyarrhythmias, myocardial ischemia, and infarction that are associated with cardiac arrhythmias. Although research in this area dates back to early part of the 19th century, we still lack the ...
Kuklik P - - 2004
Adequate description of heart muscle electrical activity is essential for the proper treatment of cardiac arrhythmias. Contemporary mapping and ablating systems allow a physician to introduce an electrode (catheter) into the human heart, to measure the position of the electrode in space and, simultaneously, the electrical activity timing and the ...
De Groot Joris R - - 2004
Sudden cardiac death forms a major cause of mortality. Myocardial ischemia-induced ventricular fibrillation (VF) is frequently the underlying mechanism. Ventricular arrhythmias arise in two distinct phases during the first hour of ischemia. The first, the 1A phase, has been extensively studied, and few studies relate to the 1B phase. The ...
Katritsis Demosthenes G - - 2004
The coronary sinus provides access to the epicardial space of the heart allowing ablation of epicardial accessory pathways, foci of ventricular arrhythmia, and arrhythmogenic areas such as the vein or ligament of Marshall. In addition, its musculature may form atrioventricular accessory connections, participate in macroreentrant atrial arrhythmias, and generate foci ...
Zawadzka-Bartczak Ewelina K - - 2004
Abrupt onset and offset of acceleration induces hemodynamic changes that activate a number of reflex cardiovascular responses. At high +Gz on a centrifuge, apparently healthy subjects occasionally develop a serious cardiac arrhythmia such as supraventricular tachycardia or asystole. We report on four such cases and examine the effect of rapid ...
Baker Kathryn E - - 2004
Various putative drug targets for suppression of ischaemia-induced ventricular fibrillation (VF) have been proposed, but therapeutic success in the suppression of sudden cardiac death (SCD) has been disappointing. Platelet-activating factor (PAF) is a known component of the ischaemic milieu. We examined its arrhythmogenic activity, and its interaction with two other ...
Steen Virginia - - 2004
The heart is one of the major organs involved in scleroderma. Cardiac involvement can be manifested by myocardial disease, conduction system abnormalities, arrhythmias, or pericardial disease. Additionally, scleroderma renal crisis and pulmonary hypertension lead to significant cardiac dysfunction secondary to damage in the kidney and lung. This report summarizes the ...
Spier Alan W - - 2004
OBJECTIVE: To evaluate spontaneous variability in the frequency of ventricular arrhythmias and assess the influence of day of ECG recording and day of week on arrhythmia frequency in Boxers affected with arrhythmogenic right ventricular cardiomyopathy (ARVC). DESIGN: Prospective study. ANIMALS: 10 Boxers with ARVC with prior ambulatory ECG recordings that ...
Teraoka Kunihiko - - 2004
Fibrotic lesions in the myocardium exhibit delayed contrast enhancement (DCE) on MR images. On the other hand, plexiform fibrosis is observed in hypertrophic cardiomyopathy (HCM), indicating an association of this condition with the pathogenesis of heart failure and arrhythmia. To examine the occurrence and extent of DCE and its relation ...
André-Petersson Lena - - 2004
BACKGROUND: Ventricular arrhythmia is a risk factor for myocardial infarction and mortality but many individuals with this abnormality live long and healthy lives. The aim of this study is to analyse the prognostic significance of frequent and complex ventricular arrhythmia in men who differed regarding ability to adapt to a ...
Saitto Carlo - - 2004
BACKGROUND: Coronary care units (CCUs) currently treat a variety of diseases, but little is known about the effectiveness of CCUs on heart conditions other than acute myocardial infarction. OBJECTIVES: The objectives of this study were to evaluate the association between direct admission to CCUs and the risk of inhospital death ...
Zhou Haiying - - 2004
The current techniques used to diagnose cardiac arrhythmias such as Holter, Rtest and telemetry systems are partially efficient because they are limited either in time or in space. In this paper, a platform dedicated to the real-time remote continuous cardiac arrhythmias detection and monitoring is proposed. Such a platform allows ...
Sreeram N - - 2004
The fetal magnetocardiogram (FMCG) can be reliably recorded from approximately the 15th week of gestation onwards. The MCG has the ability to accurately record cardiac time intervals, and to provide a real-time recording that reflects cardiac electrical activity. Standardisation of the recording, signal processing, and measurement techniques can result in ...
Brisinda D - - 2004
From November 5th, 2001 to May 19th, 2004, 545 patients (177 with arrhythmias, 67 with WPW syndrome, 60 with Ischemic Heart Disease (IHD), 129 with different kinds of cardiomyopathy, 106 normals, 6 FMCG) have been consecutively investigated at the Catholic University of Rome, with unshielded Multichannel Magnetocardiographic Mapping (MMCG): 20 ...
Jose Vinu M - - 2004
The study was conducted to determine the effects of boiled extract of Cleistanthus collinus on rats by observing ECG changes and electrolyte levels in serum and urine. Influence of minoxidil and glibenclamide on Cleistanthus collinus induced toxicity was determined. ED50 for arrhythmia, changes in contractility and heart rate were recorded ...
Krome Charles N - - 2003
The use of over-the-counter dietary supplements has risen dramatically, and adverse events can be severe. Physicians should recognize the dangers that ephedrine-containing supplements present and remain vigilant for sympathomimetic symptoms in young, otherwise healthy, patients. This case illustrates how the use of a popular weight-loss supplement by a 27-year-old professional ...
Eaton Michael P - - 2003
PURPOSE: Ventricular arrhythmias are common during ungated shock wave lithotripsy. We determined whether lithotripsy induced arrhythmias are associated with myocardial damage. MATERIALS AND METHODS: A total of 51 patients presenting for shock wave lithotripsy for right renal stones were prospectively evaluated for arrhythmias during lithotripsy. In patients with arrhythmias troponin ...
Grimm Wolfram - - 2003
BACKGROUND: Arrhythmia risk stratification with regard to prophylactic implantable cardioverter-defibrillator therapy is a completely unsolved issue in idiopathic dilated cardiomyopathy (IDC). METHODS AND RESULTS: Arrhythmia risk stratification was performed prospectively in 343 patients with IDC, including analysis of left ventricular (LV) ejection fraction and size by echocardiography, signal-averaged ECG, arrhythmias ...
Adachi N - - 2003
We report a case of life-threatening arrhythmia that was not predicted before surgery. Pulse-less ventricular tachycardia and ventricular fibrillation occurred during surgery without any changes in heart rate and blood pressure, and cardiac massage was required to maintain circulation. Although no organic stenosis was found in either the right or ...
Camm A John - - 2003
Three quite different forms of direct antiarrhythmic therapy are available for the treatment of cardiac arrhythmias: antiarrhythmic drugs, cardiac ablation and implantable devices (pacemakers and defibrillators). None of these therapies is fully effective and consequently they are increasingly combined. This combination therapy is often described as "hybrid" a term that ...
Hayashi Meiso - - 2003
Long-Term Variability in Induced Tachyarrhythmias. INTRODUCTION: Ventricular arrhythmias induced during electrophysiologic study (EPS) may vary over time, making arrhythmia induction studies unreliable. The aim of this prospective study was to clarify the clinical significance of long-term variability in induced arrhythmias and to elucidate factors determining this variability. METHODS AND RESULTS: ...
Benditt David G - - 2003
Symptoms arising from cardiac arrhythmias are often transient. Consequently, defining the responsible rhythm disturbance remains a challenge. However, absent a confident diagnosis of the arrhythmic basis for the symptoms, it is not possible to develop an effective treatment strategy. The implantable loop recorder (ILR) has become a valuable element in ...
Cheng Yuanna - - 2004
Investigation of the mechanisms of arrhythmia genesis and maintenance has benefited from the use of optical mapping techniques that employ excitation-contraction uncouplers. We investigated the effects of the excitation-contraction uncouplers 2,3-butanedione monoxime (BDM) and cytochalasin D (Cyto D) on the induction and maintenance of arrhythmia by electric shocks. Electrical activity ...
Bithal P - - 2003
Three hundred and ninety-seven patients undergoing posterior cranial fossa surgery in the sitting position were prospectively studied to evaluate the incidence of venous air embolism (VAE) and its effects on hemodynamics. End-tidal carbon dioxide (ETC02) tension was monitored to diagnose VAE. A sudden and sustained decrease in ETC02 of more ...
de Marchena Eduardo - - 2003
BACKGROUND: Several mechanisms have been proposed for ventriculophasic sinus arrhythmia: phasic changes in baroreceptor mediated vagal input to the sinus node, mechanical effects and pressure changes caused by ventricular systole, and increased blood flow to the sinus node. We attempt to elucidate the role of SA nodal blood flow in ...
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