Search Results
Results 401 - 450 of 1513
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Park Mi Young - - 2008
BACKGROUND: This study aimed to demonstrate the long-term prognostic implication of left atrial appendage (LAA) mechanical reserve determined after electrical cardioversion (CV) of atrial fibrillation (AF). METHODS AND RESULTS: 53 successfully cardioverted chronic AF patients were studied (M/F =40/13, mean age =59+/-3). LAA emptying velocity (LAAEV) and filling velocity (LAAFV) ...
Carson Wangden - - 2008
BACKGROUND: The patho-physiology of initiation of atrial fibrillation (af) or flutter (AF) is not known. Would it be possible that the real explanation is hidden in physics territory but not in medicine? Could it be possible that the heart behaves like a biological generator in physics? Can an abnormal inscription ...
Grubitzsch Herko - - 2008
BACKGROUND: Atrial fibrillation (AF) causes electrical, contractile, and structural remodeling of the atria. We investigated remodeling in patients undergoing AF ablation. METHODS: Concomitant ablation of permanent AF, lasting 1 to 240 months, was performed in 73 patients (49.3% men) with a mean age of 66 +/- 9.1 years undergoing mitral ...
Themistoclakis Sakis - - 2008
BACKGROUND: Several studies have reported early (EAT) and late (LAT) atrial tachyarrhythmias following atrial fibrillation (AF) ablation, but the factors associated with them and their clinical significance are not well known. OBJECTIVE: The purpose of this study was to investigate the predictors and the relationship between EAT and LAT after ...
Dibs Samer R - - 2008
BACKGROUND: The mechanisms of persistent human atrial fibrillation (AF) are not well understood. OBJECTIVE: The purpose of this study was to examine whether left atrial (LA) drivers are present in persistent AF by performing a comprehensive evaluation of atrial activation frequency and organization using multisite atrial recordings and correlating the ...
Khadjooi K - - 2008
OBJECTIVE: To compare the effects of cardiac resynchronisation therapy (CRT) in patients with heart failure (HF) in either atrial fibrillation (AF) or sinus rhythm (SR). DESIGN: Prospective observational study. PATIENTS: 295 consecutive patients with HF (permanent AF in 66, paroxysmal AF in 20, SR in 209; New York Heart Association ...
Workman Antony J - - 2008
Atrial fibrillation (AF) causes substantial morbidity and mortality. It may be triggered and sustained by either reentrant or nonreentrant electrical activity. Human atrial cellular refractory period is shortened in chronic AF, likely aiding reentry. The ionic and molecular mechanisms are not fully understood and may include increased inward rectifier K(+) ...
Ohara Kazumasa - - 2009
BACKGROUND: The present study was conducted to investigate whether an accumulation of clinical risk factors for thromboembolism would correlate with severity of blood stasis in the left atrium (LA) and aortic atherosclerosis in patients with nonvalvular atrial fibrillation (NVAF). METHODS: Risk levels of thromboembolism were assessed in 515 (mean age ...
Shin Sung-Hee - - 2008
BACKGROUND: Recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) is not uncommon, and the predictors of AF recurrence are not completely understood. This study aimed to investigate the clinical and echocardiographic factors associated with AF recurrence after RFCA. METHODS AND RESULTS: Sixty-eight patients with AF who had undergone ...
Santamarta D - - 2008
BACKGROUND: There is general consensus that a successful endoscopic third ventriculostomy is usually followed by a decrease of ventricular size without reaching their normal size. This study was performed to determine how the change related to clinical outcome, how it developed chronologically and whether the change in ventricular size was ...
Ermengol Valles
Atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation. On the ECG fibrillatory (f) waves (rapid oscillations with variable amplitude, shape and timing) replace normal P waves. Ventricular response becomes irregular and rapid depending of the intrinsic electrophysiological properties of the AV node1 and the balance between ...
Aronow Wilbert S - - 2008
Atrial fibrillation (AF) is associated with a higher incidence of mortality, stroke, and coronary events than is sinus rhythm. Immediate cardioversion should be performed in patients with AF and acute myocardial infarction, chest pain, hypotension, severe heart failure, or syncope. Pharmacologic treatments include beta-adrenergic blockade, calcium channel blockers, and amiodarone ...
Plante Isabelle - - 2008
BACKGROUND: Postoperative atrial fibrillation (AF) is a frequent complication following cardiac surgery. Risk factors leading to the development of postoperative AF are not well known and may be influenced by mutations of specific channels involved in atrial repolarization. Recently, the authors have identified three single nucleotide polymorphisms (SNPs) (R87Q, A251T ...
Platonov Pyotr G - - 2008
Despite the advancements in pharmacological and non-pharmacological management of atrial fibrillation (AF) observed during last decades, available treatment modalities and predictors of their success are still far from optimal. Understanding of pathophysiological mechanisms underlying AF and assessment of atrial electrophysiological properties using easily available non-invasive diagnostic tools such as surface ...
Kim Young M - - 2008
OBJECTIVES: Our goal was to evaluate the role of myocardial nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and plasma markers of oxidative stress in the pathogenesis of post-operative atrial fibrillation (AF). BACKGROUND: Atrial fibrillation is a common complication of cardiac surgery, leading to increased morbidity and prolonged hospitalization. Experimental evidence ...
Burashnikov Alexander - - 2008
Current pharmacologic strategies for the management of Atrial fibrillation (AF) include use of 1) sodium channel blockers, which are contraindicated in patients with coronary artery or structural heart disease because of their potent effect to slow conduction in the ventricles, 2) potassium channel blockers, which predispose to acquired long QT ...
Khasnis Atul - - 2008
Atrial fibrillation (AF) undoubtedly has become one of the most well studied arrhythmias today in terms of pathophysiology and diagnostic and therapeutic (interventional) electrophysiology. Although it lends itself to an apparently easy diagnosis on a surface ECG, myriad electromechanical mechanisms underlie its origin. An era of technology has been reached ...
Pullicino P - - 2008
BACKGROUND: Despite many prospective randomized studies defining the benefits of anticoagulation in atrial fibrillation (AF), there have been no adequate studies in cardiomyopathy (CM) in sinus rhythm. METHODS: We review the current knowledge of the risk of stroke in CM, left ventricular systolic dysfunction and heart failure as well as ...
Bajpai Abhay - - 2008
Atrial fibrillation (AF) is the most common, sustained rhythm disturbance. The prevalence of AF is increasing as people live longer. Common conditions such as hypertension and ischaemic heart disease play an important role in the development of AF. The presence of AF is associated with increased morbidity and mortality from ...
Akazawa Toshimasa - - 2008
PURPOSE: Atrial fibrillation (AF) is a frequent complication after coronary artery bypass surgery. Postoperative AF can lead to thromboembolic events, prolonged hospital stay, and increased costs. Recent reports have shown that an elevated plasma brain natriuretic peptide (BNP) level is associated with AF. The purpose of this prospective study was ...
Efremidis Michalis - - 2008
INTRODUCTION: The management of patients with heart failure and atrial fibrillation (AF) is a medical challenge, especially in the case of patients in whom sinus rhythm or rate control cannot be achieved with optimal pharmaceutical treatment. METHODS: Thirteen consecutive patients (11 men and 2 women, 35-70 years old, median age ...
Grubitzsch Herko - - 2008
Algorithms of signal processing allow the estimation of atrial fibrillation (AF) activity from surface electrocardiograms (ECGs). To evaluate a new commercially available ECG system for AF analysis from surface potentials. Patients (n=52, mean [+/- SD] age of 68+/-9.6 years) with persistent AF (mean duration 44+/-52.2 months), referred for cardiac surgery, ...
Haghjoo Majid - - 2008
The present study was aimed to identify the preoperative, intraoperative, and postoperative predictors of AF in a pure cohort of the patients with coronary artery disease who underwent CABG surgery. Between November 2005 and May 2006, 302 consecutive patients were included in this prospective study. All the relevant clinical, electrocardiographic, ...
Diaz J J Universidad Simón Bolívar, Caracas, Venezuela. - - 2008
The goal of this study was to investigate the usefulness of nonlinear analysis in determining the success of low energy internal cardioversion (IC) in patients with atrial fibrillation (AF). Nonlinear analysis has previously been used for characterizing AF patterns, and spontaneous termination in its paroxysmal form. However, the relationship between ...
Chou Chung-Chuan CC The Second Section of Cardiology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, 199 North Tung-Hwa Road, Taipei 10591, Taiwan. - - 2008
Atrial fibrillation (AF) is a complex disease with many possible mechanisms. Studies indicate that the arrhythmogenic foci within the thoracic veins are AF initiators. Once initiated, AF alters atrial electrical and structural properties in a way that promotes its own maintenance and recurrences and may alter the response to antiarrhythmic ...
Novaro Gian M - - 2008
The development of atrial fibrillation (AF) in cardiac patients is multifactorial, including not well defined genetic factors. To determine if Asian ethnicity is associated with the development of AF in patients with coronary disease, a meta-analysis was conducted of patient-level data from 7 prospective randomized clinical trials that prospectively collected ...
Cosio Francisco G - - 2008
Atrial fibrillation (AF) is associated with impaired functional capacity and quality of life and significant morbidity and mortality. The current management approach fails to maintain stable sinus rhythm (SR) in the majority of patients. For many years, guidelines have recommended antiarrhythmic treatment of a first AF episode only if the ...
Gillinov Marc - - 2007
Atrial fibrillation (AF) is present in 30-50% of patients presenting for mitral valve surgery. If left untreated, AF in these patients is associated with increased morbidity and, possibly, increased mortality. Therefore, concomitant management of the arrhythmia is indicated in most mitral valve patients with preexisting AF. The cut-and-sew Cox-Maze III ...
Duszanska Agata - - 2007
BACKGROUND: Atrial fibrillation (AF) in patients with Wolff-Parkinson-White syndrome (WPW) may induce complex ventricular arrhythmias resulting in sudden cardiac death. It is essential to find an effective non-invasive diagnostic method allowing to select patients at risk of life-threatening arrhythmias. Our objective was to examine Doppler predictors of AF in patients ...
Stockburger M - - 2007
AIMS: Bifocal right atrial pacing (BP) has been reported to increase arrhythmia-free intervals in patients with paroxysmal atrial fibrillation (PAF) under antiarrhythmic drugs. This study compares AF burden with unifocal pacing (UP) vs BP under sotalol. METHODS: In 19 patients with PAF a DDDR pacemaker with right atrial lateral and ...
Ishii Yosuke - - 2007
Atrial fibrillation (AF) is commonly associated with rheumatic valve disease. The dilated left atrium, degeneration of the left atrial myocardium, and elevated atrial pressure all contribute to perpetuation of AF. Over the past decade, the Maze procedure has evolved into the gold standard of treatment for medically refractory AF. The ...
Blaauw Y - - 2007
Atrial fibrillation (AF) is the most common encountered sustained arrhythmia in clinical practice. The last decade the result of large 'rate' versus 'rhythm' control trials have been published that have changed the current day practise of AF treatment. It has become clear that rate control is at least equally effective ...
Crawford Thomas C - - 2008
BACKGROUND: A better understanding of the mechanisms of recurrent atrial fibrillation (AF) after radiofrequency ablation of complex, fractionated atrial electrograms (CFAEs) may be helpful for refining AF ablation strategies. METHODS AND RESULTS: Electrogram-guided ablation (EGA) was repeated in 30 consecutive patients (mean age = 59 +/- 8 years) for recurrent ...
Echahidi Najmeddine - - 2008
BACKGROUND: Several complications may occur during catheter ablation for atrial fibrillation (AF). We report an unusual case of left atrial wall hematoma without pericardial effusion secondary to a right inferior pulmonary vein (PV) laceration. The use of real-time transesophageal echocardiography (TEE) during the procedure can be useful for early detection ...
Mariscalco Giovanni - - 2008
OBJECTIVE: Postoperative atrial fibrillation (AF) is a vexing problem in cardiac surgery. Our aim was to identify risk factors between surgical procedures, all having cardiopulmonary bypass (CPB) in common, and how AF contributes to early and late mortality. METHODS: Patients were reviewed during a 10-year period, comprising coronary artery bypass ...
Ariyarajah Vignendra - - 2008
Atrial fibrillation (AF) is common during the course of acute myocardial infarction and is associated with left atrial (LA) dilatation. However, the role of LA depolarization abnormality on the electrocardiogram (ECG) in the setting of LA dilatation was not studied in this context. Patients admitted with non-ST-segment elevation myocardial infarction ...
Pruvot Etienne - - 2007
AIMS: Experimental models have reported conflicting results regarding the role of dispersion of repolarization in promoting atrial fibrillation (AF). Repolarization alternans, a beat-to-beat alternation in action potential duration, enhances dispersion of repolarization when propagation velocity is involved. METHODS AND RESULTS: In this work, original electrophysiological parameters were analysed to study ...
Platonov Pyotr G - - 2007
Areas of slow conduction and conduction block are important prerequisites for re-entry known to underlie atrial fibrillation (AF). Experimental and clinical data show that AF is associated with global lowering of atrial propagation velocity and the presence of defects in the interatrial conduction routes. The increasing data from anatomical studies ...
Korantzopoulos Panagiotis - - 2007
End-stage renal disease (ESRD) is associated with increased cardiovascular morbidity and mortality. Recent studies indicate that atrial fibrillation (AF) is prevalent among ESRD patients while it adversely affects the clinical outcome. Despite these considerations, AF management in this population is problematic. Notably, most ESRD patients with AF are deprived of ...
Regan Christopher P - - 2008
Drug discovery efforts have focused recently on atrial-selective targets, including the Kv1.5 channel, which underlies the ultrarapid delayed rectifier current, I(Kur), to develop novel treatments for atrial fibrillation (AF). Two structurally distinct compounds, a triarylethanolamine TAEA and an isoquinolinone 3-[(dimethylamino)-methyl]-6-methoxy-2-methyl-4-phenylisoquinolin-1(2H)-one (ISQ-1), blocked I(Kur) in Chinese hamster ovary cells expressing human ...
Adelstein Evan - - 2008
BACKGROUND: In patients with cardiac resynchronization therapy (CRT) devices, right atrial (RA) pacing introduces a significant prolongation in interatrial conduction time, delaying left atrial mechanical systole and curtailing left ventricular filling. The resultant increase in left-sided filling pressures may facilitate atrial fibrillation (AF). We sought to determine whether the extent ...
Marcus Gregory M GM Electrophysiology Section, Division of Cardiology, University of California, San Francisco, CA 94143-1354, USA. - - 2008
Previous studies suggest that markers of inflammation are elevated in patients with atrial fibrillation (AF). However, because inflammation has been implicated in contributing to risk of both AF and coronary artery disease (CAD), which are often present in the same populations, it is important to control for confounding by the ...
Sakabe Masao - - 2007
BACKGROUND: There is epidemiological evidence that omega-3 polyunsaturated fatty acids (PUFAs) reduce the risk of atrial fibrillation (AF), but clinical data are conflicting. The present study assessed the effects of PUFA on AF in experimental models. METHODS AND RESULTS: We studied the effects of oral PUFA supplements in 2 experimental ...
Afzal Ali R - - 2008
BACKGROUND: Atrial fibrillation (AF) is a common arrhythmia encountered following cardiac surgery. Previously, we have shown that higher expression of heat shock protein (HSP) 70 was associated with decreased incidence of postoperative AF (PoAF), suggestive of an antiarrhythmic role. OBJECTIVE: We have hypothesised that Met493Thr substitution of one of the ...
Verma Atul - - 2008
BACKGROUND: Complex fractionated electrograms (CFEs) are continuous electrograms (EGMs) of very short cycle length (CL) representing substrate for atrial fibrillation (AF) perpetuation. Ablation of CFEs may result in AF slowing, termination, and prevention, but identifying them can be subjective. OBJECTIVE: The purpose of this study was to prospectively assess (1) ...
Eshoo Suzanne - - 2008
BACKGROUND: There is no well established measurement of left atrial (LA) size on transoesophageal echocardiography (TOE). We sought to determine which measurement on TOE would best correlate with LA size obtained from transthoracic echocardiography (TTE). METHODS: LA diameter (LAD) and volume (LAV) on TOE were compared to TTE measurements from ...
Niwano Shinichi - - 2007
BACKGROUND: Continuous rapid atrial stimulation causes atrial remodeling, but little is known about the difference in the arrhythmogenicity of the left (LA) and right atria (RA). METHODS AND RESULTS: In 14 beagle dogs, continuous rapid pacing (400 beats/min) was delivered from the right (n=7) or left (n=7) atrial appendage (RAA ...
Fung Jeffrey W H - - 2007
BACKGROUND: The clinical significance of atrial fibrillation (AF) in heart failure with normal ejection fraction (HFNEF) remains undetermined. METHODS AND RESULTS: We compared the clinical and echocardiographic characteristics among 238 patients hospitalized for HF. Using the cutoff of left ventricular EF of 50%, there were 146 patients with HFNEF (AF ...
Chrysostomakis Stavros I - - 2007
Using a goat animal model, we tested the hypothesis that angiotensin-II inhibition reduces fibrotic degeneration of both the atrial and ventricular myocardium as well as AF induction susceptibility. We studied three groups of five goats over a 6-month period. The study animals in the first two groups were implanted with ...
Kirchhof Paulus - - 2007
Atrial fibrillation (AF), the most common atrial arrhythmia, has a complex aetiology and causes relevant morbidity and mortality due to different mechanisms, including but not limited to stroke, heart failure, and tachy- or bradyarrhythmia. Current therapeutic options (rate control, rhythm control, antithrombotic therapy, 'upstream therapy') only prevent a part of ...
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