Search Results
Results 501 - 550 of 1467
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Luo Jijian - - 2004
BACKGROUND: Local ventricular refractoriness and its dispersion during ventricular fibrillation (VF) have not been well evaluated, due to methodological difficulties. METHODS: In this study, a non-invasive method was used in evaluation of local ventricular refractoriness and its dispersion during induced VF in 11 patients with VF and/or polymorphic ventricular tachycardia ...
Sosa Eduardo - - 2004
INTRODUCTION: The subxyphoid pericardial mapping approach can be used to facilitate catheter ablation of postmyocardial-infarction ventricular tachycardia (post-MI VT), but the presence of dense adhesions is thought to preclude this approach in patients who have previously undergone open-chest cardiac surgery. AIMS OF THE STUDY: This study reports the first use ...
Sinha Anil-Martin - - 2004
INTRODUCTION: Inadequate therapy for supraventricular tachyarrhythmias (SVT) is a frequent problem of implantable cardioverter defibrillators (ICD). Dual-chamber ICDs have been developed to improve discrimination of SVT from ventricular tachycardia (VT). We investigated the positive predictivity, sensitivity, and specificity of a new algorithm, the SMART detection trade mark algorithm, incorporated in ...
Bhatia Atul - - 2004
Since the introduction of the implantable cardioverter defibrillator (ICD) for the management of patients with high risk of arrhythmic SCD, there has been increasing use of this device. Its basic promise to effectively terminate ventricular tachycardia (VT)-ventricular fibrillation (VF) has been repeatedly met. In several randomized trials, the ICD has ...
Ozin Bülent - - 2004
In this report, we describe an unusual case of right ventricular outflow tract (RVOT) tachycardia with episodes of repetitive monomorphic ventricular tachycardia (VT), paroxysmal sustained VT and incessant monomorphic VT of the same morphology. Diltiazem, adenosine, or metoprolol failed to interrupt these arrhythmias. However, administration of intravenous propafenone completely eliminated ...
Glikson Michael - - 2004
INTRODUCTION: Evidence is inconclusive concerning the role of implantable cardioverter defibrillators (ICDs) to treat patients with hemodynamically stable ventricular tachycardia (VT). The goal of this study was to estimate future risk of unstable ventricular arrhythmias in patients who received ICDs for stable VT. METHODS AND RESULTS: We reviewed complete ICD ...
Wolpert C - - 2004
To assess the incidence and electrophysiological characteristics of spontaneous ventricular tachyarrhythmias after implantable cardioverter-defibrillator (ICD) implantation for primary prevention. Prospective observational study. 41 consecutive patients, who fulfilled MADIT (multicenter automatic defibrillator implantation trial) I criteria, except for suppressibility by procainamide, and who received a prophylactic ICD. Subpectoral implantation of an ...
Soejima Kyoko - - 2004
OBJECTIVES: The purpose of this study was to evaluate the occurrence, locations, and relationship of ventricular tachycardia (VT) to low-voltage areas in dilated cardiomyopathy (DCM). BACKGROUND: The substrate causing monomorphic VT after infarction is characterized by regions of low-voltage (<1.5 mV) scar on electroanatomic maps. The substrate causing VT associated ...
Mehta Rajendra H - - 2004
OBJECTIVES: We sought to evaluate the incidence, predictors, and outcomes of ventricular tachycardia and/or ventricular fibrillation (VT/VF) in the cardiac catheterization laboratory among patients undergoing primary percutaneous coronary intervention (PCI). BACKGROUND: Although VT/VF has been known to occur during primary PCI, the current data do not identify patients at risk ...
Ascione Raimondo - - 2004
OBJECTIVES: We sought to investigate the relationship between perioperative factors and the occurrence of ventricular tachycardia (VT) and ventricular fibrillation (VF), as well as the impact of VT/VF on early and late mortality. BACKGROUND: Both VT and VF are rare but serious complications after coronary artery bypass graft surgery (CABG), ...
Aizawa Yoshifusa - - 2004
Since the first clinical use of implantable defibrillator in human, the technology and the function of implantable cardioverter-defibrillator (ICD) have been much improved and now, ICD can be implanted within the chest wall. ICD is the most reliable therapy to prevent sudden cardiac death (SCD) in patients with documented VT/VF ...
Betsuyaku Tetsuo - - 2004
INTRODUCTION: Remodeling of gap junctions has been implicated in development of ventricular arrhythmias following myocardial infarction (MI) but the specific contribution of reduced electrical coupling is not known. We addressed this question using hearts from mice heterozygous for a connexin43 null allele (Cx43(+/-)). METHODS: To determine whether Cx43-deficient mice exhibit ...
Nakane Eisaku - - 2004
A 62-year-old female with palpitations was admitted to hospital where she recorded 12,299 monofocal ventricular premature contractions (VPCs) in 24 h and nonsustained ventricular tachycardia (VT) on exertion. She had hypokalemia with renal potassium wasting, a chloride-resistant metabolic alkalosis, elevated plasma renin, elevated plasma aldosterone (relative to the serum K ...
Nanthakumar Kumaraswamy - - 2004
OBJECTIVE: The objective of this study was to test the hypothesis that on the epicardium of the in vivo human heart, ventricular fibrillation (VF) consists of chaotic small wavefronts that constantly change paths. BACKGROUND: Despite the significance of VF to cardiovascular mortality, little is known about the wavefronts that constitute ...
Lilleberg Jyrki - - 2004
BACKGROUND: Levosimendan is a calcium sensitizer that increases the contractility of the myofilaments and is considered not to affect cardiac electrophysiology. We assessed its potential to generate cardiac arrhythmias by analysing ECG recordings from clinical studies on intravenously administered levosimendan in heart failure patients. METHODS AND RESULTS: The database consisted ...
Berruezo Antonio - - 2004
BACKGROUND: Some ventricular tachycardias (VTs) originating from the epicardium are not suitable for endocardial radiofrequency ablation and require an epicardial approach. The aim of this study was to define the ECG characteristics that may identify an epicardial origin of VTs. METHODS AND RESULTS: We analyzed the 12-lead ECG recordings during ...
Tanno Kaoru - - 2004
BACKGROUND: Microvolt T-wave alternans (TWA) is reported to be closely associated with sudden cardiac death (SCD) and ventricular tachycardia (VT). Animal experiments revealed that microvolt TWA is highly dependent on heart rate. The purpose of this study was to determine whether patients with TWA at relatively low heart rates have ...
Kawahara Koichi - - 2004
Ventricular tachycardia (VT) is considered to be the most common precursor of ventricular fibrillation (VF). However, the mechanisms underlying the transition from VT to VF remain unclear. Here, we investigated whether and how perfusion of the heart with verapamil, a blocker of L-type calcium channels, changed the macro-dynamics of the ...
Furushima Hiroshi - - 2004
BACKGROUND: Cardiac sarcoidosis is increasingly recognized and is associated with poor prognosis. Ventricular tachycardia (VT) associated with cardiac sarcoidosis is the most likely cause of sudden death in most patients, but the mechanism has not been well established. HYPOTHESIS: This study investigated the mechanisms and outcome of VT associated with ...
Khairy Paul - - 2004
BACKGROUND: Studies have consistently shown that ventricular tachycardia (VT) and sudden cardiac death (SCD) complicate the long-term outcome after tetralogy of Fallot repair, yet the diagnostic and predictive value of electrophysiological testing in this population is uncertain. METHODS AND RESULTS: A multicenter cohort of 252 patients with repaired tetralogy of ...
del Monte Federica - - 2004
Abnormal intracellular Ca(2+) cycling plays an important role in cardiac dysfunction and ventricular arrhythmias in the setting of heart failure and transient cardiac ischemia followed by reperfusion (I/R). We hypothesized that overexpression of the sarcoplasmic reticulum Ca(2+) ATPase pump (SERCA2a) may improve both contractile dysfunction and ventricular arrhythmias. Continuous ECG ...
Sosnowski Maciej - - 2004
OBJECTIVE: The purpose of this study was to determine the characteristics and predictive value of the variability of coupling interval of ventricular premature beats (VPBs) for cardiac mortality in patients with coronary artery disease (CAD). BACKGROUND: Frequent VPBs have been linked to an increased risk for cardiac death in patients ...
De Rosa Gabriella - - 2004
Catecholaminergic polymorphic ventricular tachycardia (VT) is a rare arrhythmogenic disorder, which may cause sudden death and whose relationships with mutations in cardiac ryanodine receptor gene have been recently established. The present article reports a catecholaminergic polymorphic VT case of a 9-year-old girl, without any previous history of syncope, who has ...
Whang William - - 2004
BACKGROUND: Left ventricular ejection fraction (LVEF) predicts device discharges in patients with implantable cardioverter-defibrillators (ICDs). The relationship between severity of congestive heart failure (CHF) and ICD discharges is less clear. METHODS AND RESULTS: We prospectively analyzed the association between CHF and risk of appropriate ICD discharges in the Triggers Of ...
Matsushita Takehiko - - 2004
BACKGROUND: Although inducible ventricular fibrillation (VF) has been used as an indication for prophylactic implantation of cardioverter-defibrillators (ICDs) in patients with coronary artery disease (CAD), the significance of inducible VF remains controversial. METHODS: Among 364 CAD patients who underwent electrophysiologic (EP) study for risk stratification, 23 patients, 12 without any ...
Newton Jonathan C - - 2004
We quantified ventricular fibrillation (VF) activation rate, conduction block, and organization transmurally in pigs and dogs, whose transmural Purkinje distribution differ. In six pigs and five dogs, 75 to 100 plunge needles, containing four electrodes for the right ventricle (RV) and six electrodes for the left ventricle (LV) and septum, ...
Nakazawa Makoto - - 2004
BACKGROUND: Arrhythmia is a major late complication in adults with repaired tetralogy of Fallot, although a large-scale study has not been carried out in Japan. METHODS AND RESULTS: A nationwide multicenter study with 512 operative survivors was performed. Actuarial survival rate at 30 years (maximum follow-up) was 98.4%. Fifty-four patients ...
Bogun Frank - - 2004
BACKGROUND: In postinfarction patients, isolated potentials separated by an isoelectric segment from the ventricular electrogram indicate areas of block. Isolated potentials can be recorded during both sinus rhythm and ventricular tachycardia (VT). In an attempt to differentiate bystander pathways from critical sites within a reentry circuit, we compared the relative ...
Gilmour Robert F RF - - 2004
Sudden cardiac death, secondary to ventricular fibrillation (VF), remains the leading cause of death in many developed countries. Substantial experimental and theoretical support exists for the idea that VF is caused by spiral wave re-entry. The initiation and subsequent break-up of spiral waves have been linked to electrical alternans, a ...
Kouakam Claude - - 2004
BACKGROUND: Inappropriate therapies remain a major problem in patients with implantable cardioverter defibrillators (ICDs). Decreasing the proportion of inappropriate therapies is a major objective. With the addition of atrial detection and advanced algorithms, dual-chamber ICDs are designed to offer better discrimination of ventricular (VT) and supraventricular (SVT) arrhythmias. The present ...
Baumert M - - 2004
OBJECTIVES: Ventricular tachycardia (VT) provoking sudden cardiac death (SCD) are a major cause of mortality in the developed countries. The most efficient therapy for SCD prevention are implantable cardioverter defibrillators (ICD). In this study heart rate variability (HRV) measures were analyzed for short-term forecasting of VT in order to improve ...
Jinnouchi Yuka - - 2004
A case of a patient with sustained ventricular tachycardia (VT) undergoing implantable cardiovertor defibrillator (ICD) implantation, using transesophageal echocardiography (TEE) and near infrared spectroscopy (NIR) is described. A 67-year-old man with sustained VT associated with old myocardial infarction underwent ICD implantation. Anesthesia was induced with fentanyl and propofol and maintained ...
Hedman A - - 2004
We investigated inducibility of life-threatening arrhythmias with programmed ventricular stimulation (PVS) in relation to clinical markers of sudden cardiac death (SCD) in subjects with hypertrophic cardiomyopathy (HCM) attributable to the Asp175Asn mutation in the alpha-tropomyosin gene (TPM1-Asp175Asn). PVS was performed with up to three extrastimuli and distribution of markers of ...
Sharma Arjun D - - 2004
VF is induced during ICD implantation to determine efficacy of therapy. Establishing the best clinical method of induction of VF would potentially be beneficial in reducing the number of induction attempts and reducing the frequency of inadvertent induction of VT. Commonly used methods to induce VF include shock in the ...
Khadra L L Hijawii Fac. for Eng. & Technol., Yarmouk Univ., Irbid, - - 2004
Ventricular tachyarrhythmias, in particular ventricular fibrillation (VF), are the primary arrhythmic events in the majority of patients suffering from sudden cardiac death. Attention has focused upon these articular rhythms as it is recognized that prompt therapy can lead to a successful outcome. There has been considerable interest in analysis of ...
Ito Sachiko - - 2003
INTRODUCTION: Idiopathic ventricular outflow tract tachycardia or premature ventricular contractions (OT-VTs) can originate from several different sites in the outflow tract, including the left ventricular (LV) endocardium and epicardium. The aims of this study were (1) to develop an ECG algorithm to predict the origin of OT-VT and (2) to ...
Müller Dirk - - 2003
BACKGROUND: Ischemic events and coronary deaths show seasonal variability with a peak during December and January. It remains unclear whether ventricular tachycardias (VT) and ventricular fibrillation (VF) follow a similar pattern. The purpose of this study was to investigate the annual distribution of malignant ventricular arrhythmias. METHODS: Over a period ...
Kitamura Hidetsuna - - 2003
Nonischemic dilated cardiomyopathy (DCM) is associated with a high risk of sudden cardiac death. Signal-averaged electrocardiography (SAECG) is a useful clinical tool for detecting late ventricular potentials (LP). Gap junction alterations have recently been shown to be involved in the pathogenesis of ventricular arrhythmias in DCM; however, the possible relationship ...
Nishiuchi Tatsuya - - 2003
PURPOSE: To clarify the incidence and survival rate of bystander-witnessed out-of-hospital cardiac arrests (OHCA) with cardiac etiology in Osaka Prefecture, Japan, with a population of nearly 9 million according to the Utstein style. SUBJECTS AND METHODS: 5047 consecutive OHCA cases were treated by ambulance personnel during the 12-month period starting ...
Hermida Jean-Sylvain - - 2003
AIMS: Risk-stratification of asymptomatic Brugada Syndrome (BS) patients remains a key-issue. A typical spontaneous BS-ECG pattern and ventricular tachycardia (VT)/ventricular fibrillation (VF) inducibility are two recognized risk markers. The aim of the study was to identify additional risk markers in asymptomatic BS. METHODS AND RESULTS: We have compared Holter recordings ...
Khairy Paul - - 2003
Despite improvements in management strategies, ventricular arrhythmias remain important markers of electrical instability and contribute to the identification of patients at increased risk of sudden cardiac death post-myocardial infarction (MI). Over the past 20 years, understanding of pathophysiological mechanisms and implications of various types of ventricular arrhythmias has evolved remarkably. ...
Tsai Chia-Ti - - 2003
Little information about the ICD is available from the Asian Pacific region. The purpose of this study was to characterize the clinical features in ICD patients in Taiwan and to compare these features with those in patients in the Western populations, mainly the Canadian Implantable Defibrillator Study (CIDS), the Antiarrhythmics ...
Cain Michael E - - 2003
Reduction of sudden death requires accurate identification of patients at risk for ventricular tachycardia (VT) and effective therapies. The Multicenter Unsustained Tachycardia Trial and Multicenter Automatic Defibrillator Implantation Trials demonstrate that the implantable cardioverter defibrillator impacts favorably on the incidence of VT in patients with myocardial infarction, underscoring the need ...
Hsu Li-Fern - - 2003
We present a patient with Brugada-type ECG abnormalities and recurrent polymorphic ventricular tachycardia (VT). Subsequent investigations confirmed the diagnosis of isolated right ventricular myocardial infarction. The VT resolved after the 1st day and was not inducible subsequently. This case illustrates the importance of a careful study of the ECG to ...
Vestal Marivic - - 2003
This study reports new electrocardiographic (ECG) predictors of radiofrequency catheter ablation failure and recurrence in idiopathic right ventricular outflow tract (RVOT) ventricular tachycardia (VT) or ectopy based on 91 consecutive patients. Procedural success and failure rates were 85% (77/91) and 15% (14/91), respectively. Twenty three percent (18/77) had recurrence during ...
Horwich Tamara - - 2003
QRS prolongation on surface electrocardiography has been identified as a marker for increased cardiac mortality. A potential mechanism for increased mortality is ventricular tachycardia (VT). This study aimed to evaluate the relation between bundle branch block and sustained monomorphic VT inducibility in patients referred for electrophysiologic studies. We analyzed a ...
Strohmer B - - 2003
Frequent recurrences of ventricular tachycardia (VT) despite implantable cardioverter-defibrillator (ICD) and antiarrhythmic drug therapy are a typical indication for catheter ablation. We performed endocardial mapping of an haemodynamically tolerated VT in a 67-year-old male patient. Isolated diastolic potentials (IDPs) of similar morphology were recorded during atrial paced rhythm at baseline ...
Noda Takashi - - 2003
This case report describes two distinct morphological ventricular tachycardias (VTs) associated with bidirectional reentrant circuit around the tricuspid annulus in a 32-year-old patient with arrhythmogenic right ventricular dysplasia. Multiple radiofrequency linear ablation could abolish both VTs, and this patient has been clinically free from symptoms of VTs at 1-year follow-up.
Bode-Schnurbus L - - 2003
Patients resuscitated from ventricular tachyarrhythmias benefit from implantable cardioverter-defibrillators (ICDs) as opposed to medical treatment. Patients with increased QRS duration receiving an ICD in the presence of heart failure are at greatest risk of cardiac death and benefit most from ICD therapy. To determine whether an increased QRS duration predicts ...
Viskin Sami - - 2003
INTRODUCTION: Induction of ventricular flutter during electrophysiologic (EP) studies (similar to that of ventricular fibrillation [VF]) often is viewed as a nonspecific response with limited prognostic significance. However, data supporting this dogma originate from patients without previously documented ventricular tachyarrhythmias. We examined the significance of ventricular flutter in patients with ...
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