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Results 301 - 350 of 1461
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Yang Yanfei - - 2007
BACKGROUND: The purpose of this study is to determine whether initial vector force might best distinguish tachycardias arising from the right ventricular (RV) outflow tract (OT) versus aortic sinus cusps (ASCs). METHODS: Among 45 patients with OT tachycardia, we measured the time from the earliest QRS onset in any lead ...
Santini Massimo - - 2007
Cardiologists often are called to explain electrocardiograms of pacemaker/ implantable cardioverter (PMK/ICD) patients during arrhythmic events. The most frequent arrhythmia is atrial fibrillation (AF) whether in PMK or in ICD patients. Generally, it is not difficult to diagnose, it can affect the quality of life of this subgroup because it ...
Corlan Alexandru Dan - - 2007
OBJECTIVE: There is a continuing need of methods to identify subgroups of patients at high risk of ventricular arrhythmias, in particular after myocardial infarction (MI). METHODS: We performed a singular value decomposition of repolarization potentials in individual recordings in 134 healthy males, in 203 males with old MI and without ...
Koa-Wing Michael - - 2007
INTRODUCTION: Histological data after VT ablation in humans is rare. We present a case of a patient who had ablation for VT storm and who died remotely from non-arrhythmic causes. METHODS AND RESULTS: A 69-year-old male with ischemic cardiomyopathy and a dual-chamber implantable cardioverter defibrillator (ICD) presented with VT storm ...
Efthimiadis Georgios K - - 2007
BACKGROUND: A transmitral E/septal Ea ratio > or =15 is a predictor of adverse outcome in cardiac disease, so it was hypothesized that a septal E/Ea >/=15 would predict the risk of adverse outcome, including sustained ventricular tachycardia (VT), cardiac arrest, implantable cardioverter defibrillator (ICD) discharge, or sudden death (SD) ...
Rajappan Kim - - 2007
The treatment of ventricular tachycardia (VT) in patients with underlying ischaemic heart disease (IHD) remains a challenge. Ablation of these arrhythmias may have a significant impact on quality of life for patients. For those patients with haemodynamically unstable VT, ablation success rates have been improved by the use of non-contact ...
Flevari Panayota - - 2007
BACKGROUND: Heart rate turbulence (HRT) following isolated premature complexes is a baroreceptor-mediated prognostic marker. Short runs of spontaneous, nonsustained ventricular tachycardia (nsVT) exert a greater hemodynamic effect than extrasystoles and may trigger a more potent turbulence-like response (HRT(VT)), possibly related to other risk-related markers, such as heart rate variability (HRV), ...
Chew Huck Chin - - 2007
Fascicular ventricular tachycardia (VT; also known as left VT) belongs to a subclass of idiopathic VTs. It can be confused with VT and supraventricular tachycardia. It is an entity well recognized by the cardiology community but not as frequently by emergency medicine physicians because of its infrequency. Idiopathic left VT ...
Ten Tusscher Kirsten H W J - - 2007
Sudden cardiac death is a major cause of death in the industrialized world, claiming approximately 300,000 victims annually in the United States alone. In most cases, sudden cardiac death is caused by ventricular fibrillation (VF). Experimental studies in large animal hearts have shown that the uncoordinated contractions during VF are ...
Blangy Hugues - - 2007
AIMS: Ventricular arrhythmia is the main cause of sudden cardiac death. Intracardiac strain, myocardial and extracellular matrix remodelling, and subsequent myocardial fibrosis are involved in arrhythmia pathogenesis. The present study investigates the relationship between cardiac fibrosis [procollagen type I aminoterminal peptide (PINP), procollagen type III aminoterminal peptide (PIIINP), TIMP1, membrane ...
Fisher John D - - 2007
Patients with coronary artery disease, depressed left ventricular ejection fraction, and nonsustained ventricular tachycardia (VT) have a high mortality rate due to arrhythmic (arrhythmic death/cardiac arrest) and other cardiac causes. The Multicenter UnSustained Tachycardia Trial (MUSTT) investigated whether electrophysiologic study (EPS) was helpful in choosing drug or defibrillator therapy in ...
AIZAWA, Yoshifusa
Aims: In selecting effective antiarrhythmic agents for reentrant ventricular tachycardia (VT), there is no hallmark which can predict drug-efficacy. In this study, the ability of dl-sotalol to suppress the inducible VT was assessed during an electrophysiologic study with special reference to the zone of entrainment, an index of the excitable ...
Malhotra Surender - - 2007
Congenitally corrected transposition of the great vessels (CCTGA) is a rare congenital heart defect. Patients with CCTGA have the anatomical right ventricle as their systemic pumping chamber, with ventricular dysfunction and congestive heart failure (CHF) being relatively common in older adults. The most common presenting feature is bradycardia due to ...
Ramana Ravi K - - 2007
It is not uncommon for patients with severe ischemic or nonischemic cardiomyopathy to have recurrent ventricular arrhythmias. Many of these arrhythmias remain asymptomatic and can be controlled with beta-blockers or amiodarone. However, for a subset of these patients, the arrhythmia is persistent and requires antitachycardic pacing, internal defibrillation, or radiofrequency ...
Chun K R Julian - - 2007
Idiopathic outflow tract ventricular tachycardia (VT) can arise from the right (RVOT) or left ventricular outflow tract (LVOT). The electrocardiographic (ECG) pattern of RVOT VT is typical in most patients, showing a monomorphic left bundle branch block (LBBB) QRS morphology with an inferior axis. Radiofrequency catheter ablation can be performed ...
Denniss A Robert - - 2007
Studies from the 1980s, refined in the intervening years, have examined the milieu for ventricular tachycardia (VT) and ventricular fibrillation (VF) occurring late after acute myocardial infarction (AMI). The arrhythmogenic substrate appears to be patchy areas of fibrous tissue interdigitating with viable bundles of myocardium which have distorted orientation and ...
Ross David L - - 2007
In the absence of acute ischaemia, ventricular tachycardia (VT) is the most common arrhythmia leading to cardiac arrest and death. This paper will describe the history of research into VT and the therapies that evolved. The contributions of John Uther and other members of the Department of Cardiology at Westmead ...
Nicoletti Ilaria - - 2008
The effect of cardiac resynchronisation therapy on ventricular tachycardias (VT) has not been well established. This case-report demonstrates the favourable impact of biventricular pacing on ventricular arrhythmias. In 2004, a patient with dilated cardiomyopathy and ICD since 1999 was admitted to our Division for multiple VT. While left ventricular function ...
Engel Gregory - - 2007
BACKGROUND: We sought to evaluate the prognostic significance of premature ventricular contractions (PVCs) on a routine electrocardiogram (ECG) and to evaluate the relationship between heart rate and PVCs. METHODS: Computerized 12-lead ECGs of 45,402 veterans were analyzed. Vital status was available through the California Health Department Service. RESULTS: There were ...
Wu Suhua - - 2007
BACKGROUND: Ventricular tachycardia (VT) may be haemodynamically unstable or non-sustained, interfering with detailed activation mapping. Non-contact mapping permits beat-by-beat analysis of VT, projected upon a 3-dimensional reconstructed geometry of the cardiac chamber. Objective - The aim of the present study is to determine the utility of non-contact endocardial mapping to ...
Segal Oliver R - - 2007
OBJECTIVES: The purpose of this study was to examine the resetting response in human ventricular tachycardia (VT) circuits with 3-dimensional mapping. BACKGROUND: In characterizing re-entry with the resetting response, inferences are made about interaction of single ventricular extrastimuli (SVE) with VT. METHODS: Non-contact mapping was used to examine the effects ...
Schoels Wolfgang - - 2007
BACKGROUND: Previous studies in implantable cardioverter-defibrillator (ICD) patients demonstrated the efficacy and safety of antitachycardia pacing (ATP) for rapid ventricular tachycardias (VT). To prevent shock delay in case of ATP failure, a new feature (ATP during charging) was developed to deliver ATP for rapid VT while charging for shock. OBJECTIVE: ...
Cha Yong-Mei - - 2007
INTRODUCTION: Our objective was to determine features of ventricular tachyarrhythmias triggering appropriate implantable cardioverter-defibrillator (ICD) interventions in hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: The study cohort was 68 high-risk HCM patients who received ICDs for primary sudden cardiac death prevention from 1995 to 2003. All episodes of sustained ventricular tachyarrhythmias ...
Eberhardt Frank - - 2007
BACKGROUND: A VDD-implantable cardioverter-defibrillator (ICD) provides atrioventricular (AV) synchronous stimulation when necessary and incorporates the advantages of dual chamber arrhythmia discrimination algorithms both at potentially lower costs and less periprocedural complications than a DDD-ICD system. A prerequisite for correct dual chamber ICD function is reliable atrial sensing. METHODS: We evaluated ...
Okada Taro - - 2007
We report a case of polymorphic ventricular tachycardia and ventricular fibrillation (PVT/VF) storm associated with ischemic cardiomyopathy (ICM). The electrocardiogram (ECG) monitor revealed frequent premature ventricular contractions (PVCs) initiated PVT/VF. Electroanatomic mapping revealed the plausible origins of PVCs were located in the scar border zone at the posterior septum of ...
Chorro Francisco J - - 2007
BACKGROUND: Few experimental studies have analyzed the effects of selective radiofrequency (RF) lesions upon ventricular fibrillation (VF). The RF-induced isolation of selected zones would make it possible to determine whether these zones are essential for existence of the arrhythmia. METHODS: In 31 Langendorff-perfused rabbit hearts, the characteristics and inducibility of ...
Chen-Scarabelli Carol - - 2007
BACKGROUND: Chronic renal insufficiency (CRI) has been associated with increased risk of cardiovascular morbidity and mortality. However, there is limited knowledge regarding this association and the effect of renal dysfunction on survival benefit in patients with implantable cardioverter-defibrillators (ICDs). METHODS: We investigated whether there was an association between CRI (defined ...
Clyne Christopher A - - 2007
BACKGROUND: Acute and long-term success of catheter ablation of right ventricular outflow tract tachycardia (RVOT VT) may be limited by the inability to reproduce the arrhythmia at the time of activation (AM) and pace mapping (PM). We have observed early initiation of the clinical VT when subtherapeutic radiofrequency (RF) energy ...
Chen Wei-Yuan - - 2007
BACKGROUND: Early reperfusion in the acute phase of myocardial infarction and better medical treatment of consequent heart failure and tachyarrhythmia have decreased the incidence of massive myocardial infarction, left ventricular (LV) aneurysm and also postinfarction-sustained ventricular tachycardia (VT). However, for a number of patients, surgical ablation combined with aneurysm resection ...
Segal Oliver R - - 2007
HYPOTHESIS: Endocardial catheter ablation of ventricular tachycardia (VT) may fail if originating from epicardial or intramural locations. We hypothesized that mapping could be achieved using an angioplasty guidewire in the coronary circulation, to guide trans-coronary ablation. METHODS AND RESULTS: Six patients (2 male), 64 +/- 14 years and previously unsuccessful ...
Stokoe Kate S KS Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, - - 2007
Brugada syndrome (BrS) is associated with a loss of Na+ channel function and an increased incidence of rapid polymorphic ventricular tachycardia (VT) and sudden cardiac death. A programmed electrical stimulation (PES) technique assessed arrhythmic tendency in Langendorff-perfused wild-type (WT) and genetically modified (Scn5a+/-) 'loss-of-function' murine hearts in the presence and ...
Aryana Arash - - 2007
BACKGROUND: The present study examines the safety and feasibility of using a remote magnetic navigation system to perform endocardial and epicardial substrate-based mapping and radiofrequency ablation in patients with scar-related ventricular tachycardia (VT). METHODS AND RESULTS: Using the magnetic navigation system, we performed 27 procedures on 24 consecutive patients with ...
Pietrasik Grzegorz - - 2007
BACKGROUND: Obesity, as defined by body mass index > or =30 kg/m(2), has been shown to be a risk factor for cardiovascular disease. However, data on the relationship between body mass index (BMI) and the risk of ventricular arrhythmias and sudden cardiac death are limited. The aim of this study ...
Peichl Petr - - 2007
We report a case of a patient with nonischemic dilated cardiomyopathy and implantable cardioverter-defibrillator, in whom an upgrade to biventricular pacing triggered multiple episodes of ventricular tachycardias (VTs) of two morphologies. First VT presented as repetitive nonsustained arrhythmia of the same morphology as isolated ectopic beats, suggesting its focal origin. ...
Segal Oliver R - - 2007
INTRODUCTION: Characteristics of the 12-lead ECG during VT are used to guide initial placement of mapping catheters in endocardial ventricular tachycardia (VT) ablation. Previously constructed algorithms for guidance in human infarct-related VT are limited to patients known to have anterior or inferior infarcts only. We hypothesized that 12-lead ECG characteristics ...
Reithmann Christopher - - 2007
BACKGROUND: We describe immediate reinitiation of macroreentry ventricular tachycardia (VT) involving the His-Purkinje system by ventricular pacing from the electrode of an implantable cardioverter defibrillator (ICD) as a mechanism of VT storm refractory to ICD therapy. METHODS AND RESULTS: Repetitive reinitiation of bundle branch reentry tachycardia (BBRT), interfascicular tachycardia, or ...
Massé Stéphane - - 2007
Ventricular fibrillation (VF) is an important cause of sudden cardiac death and cardiovascular mortality in patients with cardiomyopathy. Although it was generally believed that chaotic reentrant wavefronts underlie VF in humans, there is emerging evidence of spatiotemporal organization during early VF. The mechanism of this organization of electrical activity in ...
Bauer Alexander - - 2007
Patients with sustained ventricular tachyarrhythmias are at high risk for sudden cardiac death. The mechanisms leading to multiple temporally related episodes of ventricular fibrillation (VF) are not yet fully elucidated, and treatment options are limited. We investigated whether K(ATP)-channels could be involved in triggering VF. We determined postarrhythmic changes of ...
Jafary Fahim H - - 2007
Polymorphic ventricular tachycardia and ventricular fibrillation (VF) carry important prognostic implications, especially in the post myocardial infarction period. However, artifact on the electrocardiographic tracing can mimic VF particularly on routinely recorded rhythm strips in hospitals. Such misinterpretation can lead to expensive (and potentially risky) diagnostic and therapeutic steps. We report ...
Henriques J - - 2007
An integrated framework for ventricular arrhythmias (VA) assessment, composed of two levels, is proposed in this work. The first level consists of four independent neural networks (NN), designed for specific detection tasks: signal quality, premature ventricular contractions (PVC), ventricular tachycardia (VT) and ventricular fibrillation (VF). Time and frequency domain features, ...
Shiga Tsuyoshi - - 2007
Sudden cardiac death (SCD) accounts for approximately one-third of all deaths in patients with heart failure, and is generally the result of ventricular tachycardia (VT) and/or ventricular fibrillation (VF). The mechanisms of VT/VF associated with heart failure are complex and heterogeneous; they include functional and structural remodeling, as well as ...
Lo Ronald - - 2007
Electrocautery is commonly employed during surgical implantation and explantation of pacemakers and implantable cardioverter-defibrillators (ICDs). Four cases of electrocautery-induced ventricular tachyarrhythmias including ventricular tachycardia (VT) or ventricular fibrillation (VF) during device implantation or explantation are described. METHODS: The incidence of electrocautery-induced VT or VF at Winthrop University Hospital was analyzed ...
Gualano Sarah K - - 2007
BACKGROUND: Left ventricular (LV) false chordae tendinae (false chords) have been implicated as a source of idiopathic left (IL) ventricular tachycardia (VT). However, it is unknown whether pretest bias contributes to an apparent association with disease. The purpose of this study was to determine the prevalence of false chords on ...
Kaseno Kenichi - - 2007
Few studies have clarified the prevalence and characteristics of idiopathic outflow tachycardia (OT-VT) with an altered QRS morphology after radiofrequency catheter ablation (RFCA), requiring additional RFCA applications at a different portion of the outflow tract (OT) to abolish the OT-VT. Among 344 patients (97 VTs and 247 premature ventricular contractions), ...
Shajahan T K - - 2007
Every sixth death in industrialized countries occurs because of cardiac arrhythmias such as ventricular tachycardia (VT) and ventricular fibrillation (VF). There is growing consensus that VT is associated with an unbroken spiral wave of electrical activation on cardiac tissue but VF with broken waves, spiral turbulence, spatiotemporal chaos and rapid, ...
Baumert Mathias - - 2007
Ventricular tachycardia (VT) provokes sudden cardiac death (SCD), which is a major cause of mortality in developed countries. Implantable cardioverter-defibrillators (ICDs) are an efficient therapy for SCD prevention. In this study we analyze heart rate variability (HRV) in data stored by ICDs. In 29 patients exhibiting VT episodes, the last ...
Furukawa Tetsuo - - 2006
Ventricular fibrillation (VF) is most frequent in the very early phase in acute coronary occlusion, and is triggered by the re-entrant mechanism in this phase. An inhomogeneous conduction in the ischemic myocardium would be substrates for re-entry. The aim of this study was to examine the relationship between the severity ...
Bella Paolo Della - - 2006
In recent years several trials demonstrated the efficacy of implantable cardioverter-defibrillation (ICD) therapy in reducing cardiac and total mortality in patients affected by rapid ventricular tachycardia (VT) and/or ventricular fibrillation. Nevertheless, ICD do not prevent arrhythmia recurrences, thus being a palliative and not a curative treatment modality. The tolerance to ...
Bogun Frank - - 2006
OBJECTIVES: The objective of this study was to assess the role of Purkinje fibers in monomorphic, post-infarction ventricular tachycardia (VT). BACKGROUND: Ventricular fibrillation and polymorphic VT in the setting of acute myocardial infarction (MI) may be triggered by ectopy arising from Purkinje fibers. METHODS: From among a group of 81 ...
Corbisiero Raffaele - - 2006
AIMS: Interval- and morphology-based algorithms have been used in modern implantable cardioverter defibrillators (ICDs) to discriminate supraventricular tachycardia (SVT) from other rhythms. A newly developed ICD discrimination algorithm, Rhythm ID (Guidant Corporation, St Paul, MN, USA), uses both interval-based metrics and an electrogram vector timing and correlation (VTC) algorithm in ...
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