Search Results
Results 651 - 700 of 1466
< 9 10 11 12 13 14 15 16 17 18 19 >
Swerdlow C D - - 2001
To reduce inappropriate therapy of supraventricular tachycardia (SVT), implantable cardioverter defibrillators (ICDs) include algorithms to discriminate ventricular tachycardia (VT) from SVT. Dual-chamber algorithms analyze atrial and ventricular rates or AV relationship. They provide advantages over single-chamber algorithms, but introduce new ways to detect SVT as VT inappropriately and to underdetect ...
Chen H M - - 2001
Primary cardiac lipomas are rare and are often reported as incidental findings during operations or autopsies. Lipoma-induced arrhythmia, especially ventricular tachycardia (VT), is an unusual complication of primary cardiac lipoma. We describe the case of a 43-year-old woman who presented with VT without any cardiac abnormality except for a left ...
O'Callaghan P A - - 2001
Patients with coronary artery disease and hemodynamically tolerated, highly frequent, sustained monomorphic ventricular tachycardia (VT) may undergo radiofrequency catheter ablation (RFCA) for elimination of > or = 1 morphologically distinct VTs. The purpose of this study was to evaluate the long-term clinical benefit following RFCA as a palliative treatment of ...
Shusterman V - - 2001
Cardiac cycle dynamics reflect underlying physiological changes that could predict imminent arrhythmias but are obscured by high complexity, nonstationarity, and large interindividual differences. To overcome these problems, we developed an adaptive technique, referred to as the modified Karhunen-Loeve transform (MKLT), that identifies an individual characteristic ("core") pattern of cardiac cycles ...
Kanagaratnam L - - 2001
OBJECTIVES: To describe a normal heart left bundle branch block, inferior axis ventricular tachycardia (VT), that could not be ablated from the right or left ventricular outflow tracts. BACKGROUND: Whether these VTs are epicardial and can be identified by a specific electrocardiographic pattern is unclear. METHODS: Twelve patients with normal ...
Nirei T - - 2001
To assess the significance of recovery time (RT) dispersion measured by body surface mapping, we investigated body surface RT isochrone maps of 40 patients with anterior old myocardial infarction (OMI), 40 patients with dilated cardiomyopathy (DCM), and 40 controls. Among the OMI and DCM groups, 20 patients per group had ...
Shan Q - - 2001
OBJECTIVE: To explore the characteristics of arrhythmogenic right ventricular cardiomyopathy (ARVC). METHODS: Seven patients with arrhythmogenic right ventricular cardiomyopathy and 34 members of three families were studied. All patients and family members underwent history collection, clinical examination, electrocardiogram (ECG), two-dimensional echocardiography (2-DE) and a signal averaging electrocardiogram. Programmed ventricular stimulation ...
Tan H L - - 2001
While adenosine effectively terminates most supraventricular tachycardias (SVT), rare case reports have demonstrated its proarrhythmic potential, including induction of ventricular tachycardia (VT). The aim of this study was to define the proarrhythmic effects of adenosine in a large, unselected population. During a 5-year period, adenosine was used (average dose 9.7 ...
Tsuchiya T - - 2001
OBJECTIVES: We characterized pharmacologically the slow conduction zone of verapamil-sensitive idiopathic left ventricular tachycardia (ILVT) with regard to the late diastolic potential (LDP). BACKGROUND: We showed that the slow conduction zone of ILVT could be divided into two components by LDP; that is, the distal component with a tachycardia-dependent conduction ...
KuĊ‚akowski P - - 2001
Increased QT dispersion (QTd) calculated from sinus beats has been shown to identify patients prone to sustained VT. However, predictive accuracy of this parameter is limited. Electrophysiological properties of the myocardium may be altered by a premature ventricular beats, which is a well-established trigger for sustained VT. Therefore, the author ...
Kautzner J - - 2001
Optimum strategy for radiofrequency (RF) catheter ablation of ventricular tachycardia (VT) after inferior wall myocardial infarction (MI) that originates from the posteroseptal process of the left ventricle is not known. We describe a case report of a 57-year-old man who developed recurrent post-MI VT with ECG morphology consistent with this ...
Merino J L - - 2001
BACKGROUND: Diagnosis of bundle-branch reentry ventricular tachycardia (BBR-VT) by the standard approach is challenging, and this may lead to nonrecognition of this tachycardia mechanism. Because the postpacing interval (PPI) after entrainment has been correlated with the distance from the pacing site to the reentrant circuit, BBR-VT entrainment by pacing from ...
Hunt T - - 2001
Discrimination between supraventricular tachycardia (SVT) with aberrant conduction from ventricular tachycardia (VT) is vital for the safe and effective management of both conditions. Electrocardiographic algorithms for the differentiation of broad complex tachycardia are complex and difficult to implement in the acute setting, with misdiagnosis occurring in up to 40% of ...
Xing D - - 2001
To define the relationship between ischemia-reperfusion-induced myocardial damage (IRD) and the occurrence of ventricular tachycardia (VT) and fibrillation (VF), we studied 23 dogs with a three-dimensional activation mapping system. Left anterior descending (LAD) coronary artery occlusion and reperfusion were performed while recording electrograms during VF and atrial pacing. Prior nonischemic ...
Schäfers M A - - 2001
OBJECTIVE: In recent in vivo studies using positron emission tomography (PET) our group demonstrated that the myocardial beta adrenoceptor (betaAR) density is reduced in arrhythmogenic right ventricular cardiomyopathy (ARVC) and idiopathic right ventricular outflow tract tachycardia (RVO-VT) associated with an increased presynaptic catecholamine washout. It was hypothesised that the reduction ...
Iwata M - - 2001
OBJECTIVES: We sought to define the clinical and long-term prognostic implications of autoantibodies that act against the second extracellular loop of beta1-adrenergic receptors (ARs) in patients with idiopathic dilated cardiomyopathy (IDC). BACKGROUND: Although autoantibodies directed against various domains of beta-ARs are found in patients with IDC, only a subgroup against ...
Yamaura M - - 2001
Sustained monomorphic ventricular tachycardia (VT) can be frequently entrained and interrupted with rapid pacing and the mechanism of the pacing-induced interruption is considered to be due to orthodromic block. This study focused on the incidence of VT which was interrupted at a critical cycle length and was characterized by an ...
Anastasiadis P G - - 2001
PURPOSE: The aim of the present study was to test the validity of magnetocardiography (MCG) in the estimation of neonatal cardiac rhythm using a single channel superconductive quantum interference device (SQUID). MATERIALS AND METHODS: Our study population consisted of 50 neonates who were delivered normally between 37-41 weeks of gestation ...
Ruan Y - - 2001
Presented in this paper were 3 cases of a special kind of polymorphic ventricular tachycardia (VT). The clinical manifestation was recurrent syncope without organic heart disease. The electrocardiogram (ECG) was characterized by normal QT intervals with short-coupled variant of torsade de pointes. The efficacy of treatment with class I, II, ...
Prystowsky E N - - 2001
Sudden cardiac death (SCD) affects nearly 300,000 people each year in the U.S., and out-of-hospital rates for survival range from only 2% to 25%. A substantial reduction in SCD requires primary prevention through risk-stratification and secondary prevention of sustained ventricular tachycardia (VT-S) and ventricular fibrillation (VF). Because frequent premature ventricular ...
Merino J L - - 2001
Ventricular arrhythmias (VA) have been associated with mortality in idiopathic dilated cardiomyopathy (IDCM). All 3 main mechanisms of arrhythmogenesis - reentry, trigger activity, and automatism - have been implicated. Arrhythmogenic substrates in IDCM favor these mechanisms and are often potentiated by electrolyte imbalance secondary to diuretic treatment, by antiarrhythmic drugs, ...
Taneja T - - 2000
INTRODUCTION: Little information is available on the relationship between the mode of induction of ventricular fibrillation (VF) to VF characteristics. METHODS AND RESULTS: VF was induced from the anterior left ventricle by programmed electrical stimulation, burst pacing, alternating current (AC), high current S2 at a site remote from S1, T ...
Prystowsky E N - - 2000
MUSTT and MADIT have clearly shown the survival benefit of an implantable cardioverter defibrillator (ICD) in patients with previous myocardial infarction, left ventricular ejection fraction < or = 0.40, and nonsustained ventricular tachycardia (VT), and who have had sustained VT induced at electrophysiology study. Progress in primary prevention of sudden ...
Kuo C T - - 2000
Area(s) of slow conduction are thought to be present within the reentry circuit of most clinically important ventricular tachycardia (VT). To prevent recurrence after ablation of VT late after myocardial infarction, it is desirable to localize and destroy area(s) of slow conduction "critical link" within the reentry circuit. Conventionally, they ...
Schalij M J - - 2000
BACKGROUND: Anisotropy creates nonuniformity in electrical propagation and may contribute to the occurrence of unidirectional conduction block and reentry. We describe the characteristics of reentrant tachycardia in a 2D layer of anisotropic ventricular myocardium. METHODS AND RESULTS: A Langendorff-perfused epicardial sheet (1.0+/-0.4 mm, n=35) was created by freezing the intramural ...
Farré J - - 2000
Antiarrhythmic drugs, mainly amiodarone and sotalol, radiofrequency catheter ablation, and the implantable cardioverter defibrillator (ICD) are the 3 therapeutic options in patients with sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). Idiopathic VT, incessant VT, frequently recurring, hemodynamically stable VT, and VT based on bundle branch reentry, are candidates for ...
Prystowsky E N - - 2000
Patients with coronary artery disease, nonsustained ventricular tachycardia (VT), and left ventricular dysfunction have an increased risk for sudden cardiac death. Two randomized prospective trials, the Multicenter Unsustained Tachycardia Trial (MUSTT) and the Multicenter Automatic Defibrillator Implantation Trial (MADIT), employed electrophysiologic testing for risk stratification in these types of patients. ...
Delacretaz E - - 2000
Randomized controlled trials have shown superior survival rates with implantable cardioverter defibrillators (ICDs) compared with antiarrhythmic drugs in survivors of cardiac arrest and life-threatening ventricular tachyarrhythmias, as well as in high-risk patients with ischemic heart disease and inducible ventricular tachycardia (VT). Current defibrillators are small and implanted with techniques similar ...
Lubinski A - - 2000
Experimental studies have shown that transmural dispersion of repolarization (DoR), defined as the difference in action potential duration between mid-myocardial M-cells, epicardial, and endocardial cells is reflected in the duration of the terminal portion of the T wave (TpTe) on the surface ECG. Since DoR is an important factor associated ...
Kiss O - - 2000
Intrapericardial endothelin-1 (ET-1) infusion causes dose-dependent severe ventricular arrhythmias. We examined the effects of the endothelin-A- (ETA) receptor antagonist LU 135.252 (LU) on ET-1-induced arrhythmias on six open-chest mongrel dogs. Ten minutes after an intravenous bolus of LU (5 mg/kg), ET- 1 (33 pmol/kg/min) was given into the pericardial space ...
Hachiya H - - 2000
Catheter ablation of idiopathic left ventricular outflow tract tachycardia (LVOT-VT) is rare because a safe ablation technique at this site has not been described, and serious complications may occur. This study compared the QRS morphology of LVOT-VT with that of idiopathic right ventricular outflow tract tachycardia. A comparison was made ...
Chow A W - - 2000
There are a number of limitations associated with conventional mapping for ablation of ventricular tachycardia (VT) in ischemic heart disease, such as the high recurrence rates after initially successful ablation. The development of a noncontact mapping system capable of producing high-resolution isopotential maps of the entire left ventricle has enabled ...
De Sutter J - - 2000
A Single-Center Experience. The influence, after ICD implantation, of concomitant CABG, angioplasty, and other antiischemic therapeutic interventions, like treatment with beta-blockers, on outcome and mortality of patients with VT or VF due to CAD remains uncertain. The univariate and multivariate risks of recurrence of ventricular arrhythmias requiring ICD interventions or ...
Gold M R - - 2000
The MADIT study lead to the first approved prophylactic indication for ICDs in patients with previous myocardial infarction, depressed left ventricular systolic function, nonsustained ventricular tachycardia (VT), and inducible sustained VT. However, criticisms have been raised with respect to the study design and patient selection. The MUSTT yielded similar results ...
Israel C W - - 2000
Evaluation of the quality of atrial sensing is indispensable to monitor the performance of VDD single-lead systems. In addition to counters, a new VDD system offers storage of intracardiac electrograms (EGMs). The clinical contribution of stored EGMs in a VDD pacemaker was prospectively examined in a multicenter study, and the ...
Stevenson W G - - 2000
Ventricular tachycardia (VT) due to reentry in and around regions of ventricular scar from an old myocardial infarction or cardiomyopathic process is often a difficult management problem. Radiofrequency catheter ablation is an option for controlling frequent VT episodes. Patient and VT characteristics determine the mapping and ablation approach and efficacy. ...
Grimm W - - 2000
To determine the circadian variations and the onset mechanisms of ventricular tachyarrhythmias (VT) in patients with implantable cardioverter defibrillators, stored electrograms of 364 VT episodes occurring in 40 patients with coronary artery disease (CAD) and in 29 patients with idiopathic dilated cardiomyopathy (DCM) were analyzed. A similar circadian distribution of ...
Endt P - - 2000
A new time-domain analysis method, which quantifies ECG/MCG intra-QRS fragmentation, is applied to parts of the QRS complex to identify post-myocardial infarction patients with ventricular tachycardia. Three leads of signal-averaged electrocardiograms and nine leads of magnetocardiograms were band-pass filtered (74 Hz to 180 Hz). The filtered signals showed fragmentation in ...
Shimizu A - - 2000
In a patient without apparent heart disease, a ventricular extrastimulus delivered from the left ventricular apex where the electrogram was recorded 30 ms after the onset of the QRS complex during VT advanced the second QRS complex, but not the first QRS complex. The morphology of the second QRS complex ...
Nagata M - - 2000
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a specific heart muscle disease of unknown etiology characterized by fatty and fibrofatty replacement of the right ventricular myocardium. It often manifests life-threatened ventricular arrhythmias. Previous studies have hypothesized that myocyte apoptosis contributes to the myocyte cell loss and fatty change in ARVC and ...
Dijkman B - - 2000
INTRODUCTION: Dual chamber implantable cardioverter defibrillator (ICD) technology extended ICD therapy to more than termination of hemodynamically unstable ventricular tachyarrhythmias. It created the basis for dual chamber arrhythmia management in which dependable detection is important for treatment and prevention of both ventricular and atrial arrhythmias. METHODS AND RESULTS: Dual chamber ...
Pierpont G L - - 2000
Because congestive heart failure (CHF) promotes ventricular fibrillation (VF), we compared VF in seven dogs with CHF induced by combined myocardial infarction and rapid ventricular pacing to VF in six normal dogs. A noncontact, multielectrode array balloon catheter provided full-surface real-time left ventricular (LV) endocardial electrograms and a dynamic color-coded ...
Rewers M M Copenhagen Mobile Intensive Care Unit (Kobenhavns Laegeambulance), Copenhagen Municipal Hospital, Oster Farimagsgade 3, DK-1399 K, Copenhagen, Denmark. - - 2000
To determine survival after out-of-hospital cardiac arrest (CA) in Copenhagen, according to the Utstein recommendations, and compare this with other emergency medical services systems. Register-based cohort study. Copenhagen, population 465000, area 90 km(2). Consecutive group of patients with out-of-hospital CA occurring between January 1 1991 and December 31 1993, followed ...
Zhang H X - - 2000
On the basis of non-linear dynamics, the paper uses a Lempel-Ziv complexity measure and presents a new definition of the information complexity rate: cc(n). Using such a definition, relative properties are obtained to help identify chaotic process accurately. Applying complexity analysis to abnormal ECGs recorded from patients with an implantable ...
Hastings H M - - 2000
Ventricular fibrillation (VF) remains a major cause of death in the industrialized world. Alternans (a period-doubling bifurcation of cardiac electrical activity) have recently been causally linked to the progression from ventricular tachycardia (VT) to VF, a more spatiotemporally disorganized electrical activity. In this paper, we show how alternans and thus ...
Hennersdorf M G - - 2000
The analysis of t wave alternans (TWA) was introduced to identify patients with an increased risk of ventricular tachyarrhythmias. The inducibility of ventricular tachyarrhythmias and the spontaneous arrhythmic events are correlated with a positive TWA in patients with a reduced left ventricular ejection fraction and survived myocardial infarction. In contrast, ...
Gardner R A - - 2000
BACKGROUND: Despite its importance to the aeromedical community, the occupational implications of asymptomatic, nonsustained ventricular tachycardia (VT) are not well described. We sought to clarify this issue via a review of military aviators evaluated for nonsustained VT by defining event rates for sudden cardiac death, syncope, presyncope and sustained VT, ...
Chinushi M - - 2000
A 49-year-old man was referred for further treatment of sustained monomorphic ventricular tachycardia (VT) associated with cardiac sarcoidosis. During an electrophysiologic study (EP), dl-sotalol suppressed the spontaneous VT and prevented induction of VT. However, when predonisolone treatment was started, monomorphic VT recurred frequently. To terminate the VT, a temporal pacing ...
Taylor E - - 2000
INTRODUCTION: The purpose of this study was to analyze the pattern of initiation of sustained ventricular arrhythmias in patients with varying types of underlying structural heart disease. METHODS AND RESULTS: The study group consisted of 90 patients with an implantable cardioverter defibrillator. Cardiovascular diagnoses included coronary artery disease in 64 ...
De Sutter J - - 2000
Infarct size as determined by perfusion imaging is an independent predictor of mortality after implantable cardioverter defibrillator (ICD) implantation in patients with coronary artery disease (CAD) and life-threatening ventricular arrhythmias (VA). However, its value as a predictor of VA recurrence and hospitalisation after ICD implantation is unknown. Therefore, the objective ...
< 9 10 11 12 13 14 15 16 17 18 19 >