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Results 251 - 300 of 1546
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Chrysohoou Christina - - 2008
The authors sought to investigate whether serum uric acid levels are associated with systolic left and right ventricular function, as well as left atrial function in patients with newly diagnosed heart failure. The authors enrolled 106 consecutive patients (mean age 65+/-13 years). Echocardiographic and biochemical assessment was performed during the ...
Kim Young Jin - - 2008
OBJECTIVE: To determine differential findings of patent foramen ovales (PFOs) and atrial septal defects (ASDs) demonstrating interatrial shunting on coronary computed tomography (CT) angiography. METHODS: We retrospectively analyzed 15 cases of patients demonstrating a contrast jet from the left to the right atrium on CT and interatrial shunting on echocardiography. ...
Butter Christian - - 2008
INTRODUCTION: Optimizing atrial automatic capture verification based on atrial-evoked response (AER) detection requires maximizing the signal artifact ratio (SAR), that is, AER to stimulation artifact (ART). This study evaluated the effect of bipolar atrial lead position on sensed AER, ART, and SAR. METHODS AND RESULTS: A custom-made external research system ...
Richer Louis-Philippe - - 2008
Our objective was to determine whether neuronally induced atrial arrhythmias can be modified by alpha-adrenergic receptor blockade. In 30 anesthetized dogs, trains of five electrical stimuli (1 mA; 1 ms) were delivered immediately after the P wave of the ECG to mediastinal nerves associated with the superior vena cava. Regional ...
Del Colle S - - 2008
Left atrial enlargement is frequently observed in many cardiac diseases. One of the main determinants of left atrial size is ventricular diastolic function. It has recently been suggested that left atrial volume might be the morphophysiologic expression of long-term modifications induced by diastolic function. Furthermore, left ventricular remodelling, such as ...
Zhao Cuimei - - 2008
The cardiomyocytes in the superior vena cava (SVC) myocardial sleeve have distinct action potentials and ionic current profiles, but the refractoriness of these cells has not been reported. Using standard intracellular microelectrode techniques, we demonstrated in sheep that the effective refractory period (ERP) of the cardiomyocytes in the SVC (114.7 ...
Santoro Giuseppe - - 2008
BACKGROUND: Atrial arrhythmias are well known long-term complications of atrial septal defect (ASD), presumably due to chronic atrial enlargement and stretch. Surgical repair often fails to revert the arrhythmic risk despite atrial volumetric unloading, maybe as a consequence of atriotomic scar. Avoiding atrial incision, percutaneous ASD closure should result in ...
Ishii Yosuke - - 2008
BACKGROUND: Atrial tachycardia is a troublesome and medically refractory complication after surgery for atrial fibrillation. Incomplete surgical ablation during atrial fibrillation surgery can result in residual conduction over the lesions and postoperative atrial tachycardia. Intraoperative verification of conduction block would detect incomplete ablation lesions and direct repeat ablations to prevent ...
Fumoto Hideyuki - - 2008
OBJECTIVE: Occlusion of the left atrial appendage is proposed to reduce the risk of stroke in patients with atrial fibrillation. The third-generation atrial exclusion device, modified to provide uniform distribution of pressure at appendage exclusion, was assessed for safety and effectiveness in a canine model and compared with a surgical ...
Burke Stephen J - - 2008
RATIONALE AND OBJECTIVES: Evaluate the role of two-dimensional echocardiography and electrocardiographically (ECG)-gated contrast-enhanced multislice computed tomographic (MSCT) cardiac imaging to assess cardiac anatomy, specifically pulmonary venous anatomy and left atrial thrombus, in a selected group of patients before catheter-based atrial fibrillation ablation. MATERIALS AND METHODS: Left atrial anatomy and associated ...
Patanè Salvatore - - 2009
Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with CHD or mortality from cardiovascular causes ...
Saremi Farhood - - 2008
PURPOSE: To retrospectively evaluate the anatomic characteristics of the right atrial cavotricuspid isthmus (CTI) by using 64-section multi-detector row computed tomography (CT). MATERIALS AND METHODS: Institutional review board approval and waiver of informed consent were obtained for this HIPAA-compliant study. The anatomic region of the CTI was evaluated in 201 ...
Ahlsson Anders - - 2008
OBJECTIVES: To study epicardial microwave ablation of concomitant atrial fibrillation and its effects on heart rhythm and atrial function during follow-up. DESIGN: The study included 20 open-heart surgery patients with concomitant atrial fibrillation. Transthoracic echocardiography with flow and tissue Doppler recordings was performed preoperatively and at 6 months postoperatively. Blood ...
Massumi Ali - - 2008
INTRODUCTION: Diffuse transmural fibrosis and scarring limited to the area without atrial dilation or significant structural heart or other systemic disease has not been reported. We present three cases of a syndrome characterized by refractory organized atrial arrhythmias, diffuse atrial scarring with electrical silence, and mechanical paralysis in the absence ...
de Voogt W G - - 2008
Correct pacemaker (PM) diagnosis of paroxysmal atrial tachyarrhythmias is crucial for their prevention and intervention with specific atrial pacing programmes. The PM mode switch to only ventricular pacing after detection of atrial tachyarrhythmias is often used as the parameter to quantify the 'burden' of atrial tachyarrhythmias. This review addresses potential ...
Scollan Katherine - - 2008
A 4-year-old Boxer dog with a history of ventricular premature contractions was evaluated for anorexia. An electrocardiogram revealed atrial dissociation and an echocardiogram supported simultaneous mechanical atrial systole with the ectopic atrial electrical activity. This case and the supporting images provide further credence to the existence of atrial dissociation.
Marui Akira - - 2008
OBJECTIVE: Left atrial geometry and mechanical functions exert a profound effect on left ventricular filling and overall cardiovascular performance. We sought to investigate the perioperative factors that influence left atrial geometry and mechanical functions after the Maze procedure in patients with refractory atrial fibrillation and left atrial enlargement. METHODS: Seventy-four ...
Platonov Pyotr G - - 2008
BACKGROUND: Technical developments in the management of atrial arrhythmias revived interest into the detailed knowledge of atrial anatomy. The atrial septum (AS), known for its complex structure, has been particularly difficult to study, and our knowledge of the muscular bundles providing routes for intra-atrial and interatrial conduction within the AS ...
Badano Luigi P - - 2008
OBJECTIVES: Left atrial size has shown prognostic importance in a variety of cardiac conditions. Diameters, area, and volume derived from M-mode and two-dimensional (2D) echocardiography are commonly used to estimate left atrial size. However, M-mode and 2D measures of left atrial size rely on various geometrical assumptions and their accuracy ...
Stokol T - - 2008
BACKGROUND: Arterial thromboembolism (ATE) is a common complication of feline cardiomyopathy; however, the pathogenesis of ATE is unknown. HYPOTHESIS: Systemic activation of the coagulation cascade (hypercoagulability) and endothelial injury promote ATE in cardiomyopathic cats. ANIMALS: Healthy cats (n = 30) and 3 groups of cardiomyopathic cats: Group (1) left atrial ...
Miki Yuko - - 2008
Atrial overdrive provides the best opportunity to suppress atrial arrhythmias. Atrial preference pacing (APP) algorithm has been designed to achieve a high percentage of atrial pacing. The aim of this study was to assess the efficacy of APP algorithm in patients with implanted pacemakers and tachycardia-bradycardia syndrome. The subjects were ...
Bogers A J J C - - 2008
Surgical ablation for atrial arrhythmias at conversion of atriopulmonary or ventriculopulmonary Fontan to a total cavopulmonary connection is feasible with recovery of both sinus rhythm and atrial transport function. Recovery of the patient's physical condition may take up to a year. (Neth Heart J 2008;16:170-2.).
Lim Toon Wei - - 2008
BACKGROUND: Single-ring isolation of the posterior left atrium is feasible, but the incidence and mechanisms of postprocedural arrhythmias have not been described in detail. METHODS AND RESULTS: The first 100 consecutive patients (58.8+/-11.2 years old, 80 male) who underwent single-ring isolation for atrial fibrillation (66 intermittent, 18 persistent, 16 long-standing ...
Misthos Panagiotis - - 2009
The incidence of the isolated form of partial absence of the pericardium is a rare finding. The authors present a case of an isolated left sided pericardial defect with intrathoracic protrusion of the left atrial appendage found during a left upper lobectomy for lung cancer, unrecognized after serial echocardiographs and ...
Masé Michela - - 2008
Atrial flutter is a supraventricular arrhythmia, based on a reentrant mechanism mainly confined to the right atrium. Although atrial flutter is considered a regular rhythm, the atrial flutter interval (i.e., the time interval between consecutive atrial activation times) presents a spontaneous beat-to-beat variability, which has been suggested to be related ...
Knackstedt Christian - - 2008
BACKGROUND: Cardioversion (CV) success of atrial fibrillation (AF) inversely correlates to the size of the left atrium (LA). Atrial fibrillation and its most important risk factor, congestive heart failure (CHF), both induce atrial structural enlargement and fibrosis. To investigate the effect of AF and CHF on atrial dilatation and fibrosis, ...
de Gregorio Cesare - - 2008
Isolated left ventricular noncompaction is a recently recognized age-independent cardiac genetic disorder caused by heterogeneous defects in endo-myocardial morphogenesis. Transthoracic echocardiography and cardiac magnetic resonance are the most reliable techniques to make a diagnosis of the disease, noninvasively. Arrhythmic atrial and ventricular disorders have been reported in 20-50% of these ...
Ravelli Flavia - - 2008
Although atrial flutter (AFL) is considered a highly regular rhythm, small fluctuations in cycle length have been described. The mechanisms responsible for these interval oscillations have been investigated by recent studies in humans which have shown that cyclic variations in atrial volume and pressure following ventricular contraction may account for ...
Li Walter - - 2008
We measured left atrial size and function from biplane MRI data in 62 adults with thalassemia major. Age-adjusted left atrial ejection fraction was depressed in 7 out of 20 subjects having T2* < 10 ms. Left atrial size, left ventricular size and cardiac output fell with cardiac iron loading, representing ...
Arat Nurcan - - 2008
BACKGROUND: Atrial septal defect (ASD) is a common form of congenital heart defect in adults, which affects all cardiac chambers. Atrial myocardial function in patients with ASD has not yet been clearly elucidated. The aim of this study was to investigate atrial myocardial deformation properties in patients with ASDs. METHODS: ...
Thilén, Ulf
Background In patients with atrial septal defect (ASD) the P-wave is prolonged as a marker of delayed atrial conduction which is associated with atrial fibrillation. The study aim was to analyse the impact of ASD closure in adults on P-wave duration and morphology by means of signal-averaged P-waves (PSA-ECG) and ...
Mishra Archana - - 2008
M-mode echocardiography has been accepted as gold standard for measuring left atrial (LA) size. Electrocardiography (ECG) offers a simple, non-invasive, cost-effective and reproducible method to assess LA size and it is mostly in agreement with echocardiography though discrepancies exist. ECGs and echocardiograms were obtained in 100 consecutive patients suspected of ...
Wu Tong-Guo - - 2008
To investigate the value of radiographic esophageal imaging in facilitating transseptal catheterization in patients undergoing percutaneous balloon mitral valvuloplasty. A total of 468 patients were randomized into either the study group (n = 234), in which radiographic esophageal imaging by the oral administration of a contrast media took place, or ...
Kedia Gautam - - 2008
BACKGROUND: Left atrial enlargement by echocardiography is associated with adverse cardiovascular outcomes, yet the best method for assessing left atrial size has not been established. We sought to correlate the traditional left atrial diameter (LAD) measured in the parasternal view with the recently characterized left atrial volume index (LAVI). METHODS: ...
Boyd Anita C - - 2008
AIMS: There is little known about segmental atrial function in patients with atrial arrhythmias. We evaluated segmental atrial contractility using colour Doppler tissue imaging (CDTI) in patients with chronic atrial fibrillation (CAF) who were successfully restored and maintained in sinus rhythm (SR). METHODS AND RESULTS: We compared the segmental atrial ...
Zhou Sheng-hua - - 2008
BACKGROUND: The aim of this study was to evaluate the association between atrial fibrillation and atrial dilation and the spatial distribution pattern of connexin 40 in the atria of patients with coronary heart disease. METHODS: Twenty-six patients with coronary heart disease undergoing cardiac surgery for coronary artery bypass graft were ...
Kutarski Andrzej - - 2008
BACKGROUND: Analysis of high gain, signal-averaged (SA) ECG is an accepted method evaluating abnormalities of atrial repolarization--the presence of late potentials (ALP)--predictive for atrial arrhythmias. Recently it has been proven that the location of atrial leads has an influence on atrial activation and modifies the risk of atrial arrhythmias. The ...
Esperer Hans D - - 2008
BACKGROUND: Despite the growing number of studies using Lorenz (Poincaré) plots (LPs) for the analysis of heart rate variability (HRV), a possible correlation between the underlying ECG waveforms and the RR scatter plots has never been systematically studied. We report a comprehensive investigation of distinct Lorenz plot patterns (LPPs) encountered ...
Gong Hui-Ping - - 2008
Hypertension alters the diastolic properties of the left ventricle and results in deterioration in the structure and function of the left atrium. We aimed to evaluate whether olmesartan medoxomil has an effect on left atrial function in hypertensive patients. Fifty hypertensive patients and 20 controls were included in the study. ...
Aslanidi Oleg V OV School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, United Kingdom. - - 2008
Regional differences in electrical action potential (AP) properties can provide a substrate for atrial arrhythmias. We quantify such differences by developing detailed AP models for the left (LA) and right (RA) rabbit atrial cells in order to study the underlying electrophysiological mechanisms, as well as their impacts on vulnerable properties ...
Llinares R R Department of Communications of the Universidad Politecnica Valencia, Spain. - - 2008
The extraction of the Atrial Activity from the Ventricular Activity in Atrial Fibrillation episodes is a must for clinical analysis. We follow the semi Blind Source Extraction S-BSE approach to solve the problem. The proposed algorithm modifies the BSE contrast function to satisfy the prior knowledge about the spectral content ...
McElderry H Thomas - - 2008
BACKGROUND: Surgery for the treatment of atrial fibrillation may be associated with early or late postoperative atrial arrhythmias. In many cases, the arrhythmias that occur early in the postoperative course may be related to pericardial inflammation or increased catecholamine levels and tend to resolve without further therapy. In contrast, late ...
Apostolakis Efstratios - - 2008
Giant left atrium (GLA) is a condition defined when the left atrial diameter exceeds 65 mm. GLA is commonly associated with mitral valve regurgitation due to excess intracavitary pressure resulting in strain and dilation of the left atrial chamber. The mechanism of lone GLA remains unknown but is possibly related ...
Matsuo Seiichiro - - 2008
We report the case of a 71-year-old man with two atrial tachycardias evolving simultaneously and independently in two dissociated regions after extensive ablation for chronic atrial fibrillation. One tachycardia was a focal tachycardia originating from the right inferior pulmonary vein and activating the posterior left atrium with a 2:1 conduction ...
Marine Joseph E JE Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. - - 2007
The supraventricular arrhythmias include a wide spectrum of disorders including, in descending order of frequency, atrial fibrillation, atrial flutter, atrioventricular nodal reentry, Wolff-Parkinson-White syndrome, and atrial tachycardia. While not life-threatening in most cases, they may cause important symptoms, such as palpitations, chest discomfort, breathlessness, anxiety, and syncope, which significantly impair ...
Lewalter Thorsten - - 2007
BACKGROUND: In atrial-based pacing, appropriate therapy and reliable diagnostics depend on detection and discrimination of atrial signals. Accurate classification of atrial events is mainly confounded by oversensing of ventricular far-field R-wave signals (FFRW), but attempts to reject FFRWs by manipulating atrial sensitivity and/or postventricular atrial blanking period (PVAB) may result ...
Biffi Mauro - - 2007
BACKGROUND: Automatic management of atrial stimulation by verification of atrial threshold (ACM) has recently been made feasible. We investigated circadian atrial threshold variability over the long term and the predictors of successful automatic atrial threshold measurement, in order to provide practical clues for programming ACM features, in such a way ...
Chu Chih-Sheng - - 2007
Atrial electrical remodeling (ER) after spontaneous or pacing-induced atrial fibrillation has been previously described in humans. We investigated atrial ER induced by a 5-minute period of rapid atrial pacing and the pharmacologic effects of verapamil and procainamide on this atrial ER phenomenon. The atrial effective refractory periods (ERPs) at drive ...
Hull Joshua - - 2008
A 56 year-old woman presented with palpitations. Her ECG revealed PQ segment depression and a prolonged QTc. Echocardiogram revealed a 2 x 3 cm right atrial mass. The pathological diagnosis was benign cardiac fibroma. Clinicians should remember that subtle ECG changes may reflect unusual structural changes in the heart.
Mattioli Anna Vittoria - - 2008
BACKGROUND: Conversion of atrial fibrillation (A-Fib) to sinus rhythm is associated with transient mechanical dysfunction of left atrium and appendage, termed atrial stunning. OBJECTIVES: The aim of the present study was to evaluate the relationship between nutritional status and atrial stunning after conversion of A-fib. METHODS: Fifty-eight hemodynamically stable patients ...
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