Search Results
Results 601 - 650 of 1461
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Meyerfeldt Udo - - 2002
BACKGROUND: We tested whether or not heart rate variability (HRV) changes can serve as early signs of ventricular tachycardia (VT) and predict slow and fast VT in patients with an implantable cardioverter defibrillator (ICD). METHODS AND RESULTS: We studied the ICD stored 1000 beat-to-beat intervals before the onset of VT ...
Luck Jerry C - - 2002
Biventricular pacing has been introduced as a treatment for congestive heart failure. These devices presently pace and sense from two disparate ventricular sites. Antitachycardia pacing (ATP) is used for termination of sustained monomorphic ventricular tachycardia (VT) and has been incorporated with simultaneous dual site ventricular pacing for treatment of VT. ...
Al-Khatib Sana M - - 2002
BACKGROUND: The prognosis of ventricular arrhythmias among patients with non-ST-elevation acute coronary syndromes is unknown. We studied the incidence, predictors, and outcomes of sustained ventricular arrhythmias in 4 large randomized trials of such patients. METHODS AND RESULTS: We pooled the datasets of the Global Use of Streptokinase and tPA for ...
A. Kapela,R. D. Berger,A. ...
This study evaluates influence of increased heart rate on beat-to-beat variability of vector magnitude depolarisation signal in patients admitted for cardiac electrophysiology studies. Electrical variability is quantitatively assessed during normal sinus rhythm and during atrial pacing by means of the Morlet wavelet transform variance in high-frequency region of 100Hz to ...
Satullo Gaetano - - 2002
BACKGROUND: The term concealed ventricular extrasystoles defines a phenomenon in which premature beats have a cyclical distribution and manifest after a predictable number of intervening sinus beats. The extent of its spontaneous variability as well as the stability of its orderly distribution, however, have not been defined yet. The aim ...
Sala M Fiol - - 2002
BACKGROUND: Sustained ventricular tachycardia (VT) complicating the acute phase of myocardial infarction (AMI) is a quite rare event but with short-term unfavorable prognosis. The clinical characteristics as well as the therapeutic implications have not yet been well defined. HYPOTHESIS: This paper attempts to prove that VT may be considered a ...
Hsia Henry H - - 2002
Ventricular arrhythmias are common in the setting of nonischemic cardiomyopathy. The etiology for the cardiomyopathy is frequently not identified and the label of "idiopathic" is applied. Interstitial fibrosis with conduction system involvement and associated left bundle branch block characterizes the disease process in some patients and the mechanism for monomorphic ...
Kanda Munetake - - 2002
OBJECTIVES: The study examined the electrocardiographic and electrophysiologic characteristics in relation to programmed ventricular stimulation (PVS)-induced ventricular fibrillation (VF), as well as the implications of PVS-induced VF on the recurrence of cardiac events in symptomatic Brugada syndrome. BACKGROUND: Brugada syndrome is characterized by ST-segment elevation in the right precordial leads ...
Paul Thomas - - 2002
Experience with radiofrequency catheter ablation of ventricular tachycardia (VT) in pediatric patients is limited. A 5-month-old white female infant (body weight 5.5 kg) with MIDAS syndrome who suffered from incessant polymorphic VT (ventricular rates 250 to 300 beats/min) and was unresponsive to medical treatment resulting in significantly depressed left ventricular ...
Chow Anthony W C - - 2002
BACKGROUND: We investigated the relationship between wavefront curvature and slowing of conduction both within and outside the diastolic pathway of circuits causing ventricular tachycardia (VT) in the infarcted human heart. METHODS AND RESULTS: Propagation was determined around the reentrant circuits of 11 VT (cycle length, 348+/-75 ms) in 8 patients ...
Swissa Moshe - - 2002
The focal source hypothesis of ventricular fibrillation (VF) posits that rapid activation from a focal source, rather than action potential duration (APD) restitution properties, is responsible for the maintenance of VF. We injected aconitine (100 microg) into normal isolated perfused swine right ventricles (RVs) stained with 4-[beta-[2-(di-n-butylamino)-6-naphthyl]vinyl]pyridinium (di-4-ANEPPS) for optical ...
Chen Robert J - - 2002
Extracorporeal membrane oxygenation (ECMO) can be set up quickly at the bedside and provides reliable temporary mechanical circulatory support for severe heart failure. We report the case of a 56-year-old female with circulatory collapse due to sustained ventricular tachycardia and ventricular fibrillation (VT/Vf) after coronary artery bypass grafting (CABG) who ...
Brembilla-Perrot Béatrice - - 2002
OBJECTIVES: The aim of this study was to assess the ability of a non-invasive study, the signal-averaged ECG (SAECG), to predict the effect of amiodarone at ventricular level. BACKGROUND: Amiodarone is the main drug drug used in the treatment of ventricular arrhythmias. Standard ECG does not detect any change in ...
Murakawa Yuji - - 2002
The aim of this study was to test the hypothesis that a subendocardial arrhythmogenic focus makes the heart more susceptible to VF due to electrical interaction with the Purkinje network. Monofocal ventricular tachycardia (mVT) was created by injecting 5-microg aconitine into the left ventricular subepicardium (EPI-mVT, n = 8) or ...
Niels Wessel,Udo Meyerfeldt,Christine Ziehmann
Ventricular tachycardia or fibrillation (VT) as fatal cardiac arrhythmias are the main factors triggering sudden cardiac death. The objective of this investigation is to find early signs of sustained VT in patients with an implanted cardioverter-defibrillator (ICD). These devices are able to safeguard patients by returning their hearts to a ...
de Chillou Christian - - 2002
BACKGROUND: The reentrant mechanism of postinfarct ventricular tachycardia (VT) has been documented by surgical mapping analysis, but little is known about postinfarct VT circuits and the characteristics of their related protected isthmus with the use of 3D catheter mapping systems. METHODS AND RESULTS: A 3D electroanatomic mapping was performed in ...
Li Yi-Gang - - 2002
INTRODUCTION: The aim of this study was to delineate the electrophysiologic mechanisms of a novel type of ventricular tachycardia (VT) originating from the aortic sinus of Valsalva. METHODS AND RESULTS: Endocardial mapping was performed in four patients with symptomatic VT originating from the aortic sinus of Valsalva. Two patients suffered ...
Inada Kei-ichi - - 2002
A 69-year-old man was transferred to our hospital because of severe general fatigue and progressive systemic muscle weakness. He had taken 300 mg/day of cibenzoline for his sustained ventricular tachycardia (VT) for years. At the end of June 2001 he began to feel general fatigue, which slowly progressed to systemic ...
Bogun Frank - - 2002
OBJECTIVE: The mechanism by which pacing terminates ventricular tachycardia (VT) may depend on the location of the pacing site relative to the reentry circuit. The purpose of this study was to compare the mechanisms by which pacing terminates VT at left ventricular (LV) sites with and without concealed entrainment (CE) ...
Lewalter Thorsten - - 2002
Sustained monomorphic ventricular tachycardia (VT) after valve surgery represents a clinical entity with different tachycardia mechanisms. This case report describes an incessant VT after tricuspid and aortic valve replacement that did not respond to antiarrhythmic drug treatment. The tachycardia exhibited VA block and a right bundle branch block pattern with ...
Tsai Jerome - - 2002
INTRODUCTION: We recently developed an ambulatory canine model of spontaneous ventricular tachycardia (VT) and sudden cardiac death by creating myocardial infarction, complete AV block, and infusion of nerve growth factor to the left stellate ganglion. Whether or not T wave alternans is associated with the spontaneously occurring episodes of VT ...
Eckardt Lars - - 2002
Heart failure is the term used for a cardiovascular syndrome whose definition lacks uniform criteria. It is associated with a very high mortality rate. Approximately 50% of deaths in patients with heart failure are sudden, mostly due to ventricular tachycardia (VT). In severe heart failure, death may also occur due ...
Burnes J E - - 2001
The goal of this study was to experimentally evaluate a novel noninvasive electrocardiographic imaging modality during intramural reentrant ventricular tachycardia (VT). Myocardial infarction and subsequent remodeling produce abnormal electrophysiologic substrates capable of initiating and maintaining reentrant arrhythmias. Existing noninvasive electrocardiographic methods cannot characterize abnormal electrophysiologic substrates in the heart or ...
Hagendorff A - - 2001
BACKGROUND: Focussing on regional cerebral hypoperfusion during hemodynamically stable, but borderline hypotensive, sustained ventricular tachycardia (VT) experimental studies show (1) a reduction of cerebral blood flow (CBF) during tachyarrhythmias in contrast to the concept of CBF autoregulation, (2) a mediation of hypoperfusion by neuronal and humoral mechanisms, and (3) an ...
Boulos M - - 2001
OBJECTIVES: We tested the hypothesis that spatial association of low-amplitude intracardiac electrograms can identify the presence, location and extent of dysplastic regions in arrhythmogenic right ventricular dysplasia (ARVD). BACKGROUND: Arrhythmogenic right ventricular dysplasia is a right ventricular (RV) cardiomyopathy characterized pathologically by fibrofatty infiltration and clinically by a spectrum of ...
Niels Wessel,Norbert Marwan,Udo Meyerfeldt,Alexander ...
Ventricular tachycardia or fibrillation (VT) as fatal cardiac arrhythmias are the main factors triggering sudden cardiac death. The objective of this recurrence quantification analysis approach is to find early signs of sustained VT in patients with an implanted cardioverter-defibrillator (ICD).
Grönefeld G C - - 2001
Inappropriate therapy of SVTs by ICDs remains a major clinical problem despite enhanced detection criteria like "sudden onset" and "rate stability" in third-generation devices. Electrogram morphology discrimination offers an additional approach to improve discrimination of supraventricular tachycardia (SVT) from ventricular tachycardia (VT). In a prospective, multicenter study, patients received an ...
Caron M F - - 2001
OBJECTIVE: To delineate amiodarone's role in the new American Heart Association guidelines for ventricular tachyarrhythmias, review the literature that supports the use of amiodarone in ventricular tachyarrhythmias, describe the pharmaceutical properties of amiodarone and elucidate their clinical implications, and discuss the dosing, preparation, and administration of amiodarone. DATA souRcEs: A ...
Ulgen M S - - 2001
Depressed heart rate variability and presence of ventricular late potentials in acute myocardial infarction are associated with a poor prognosis. Although it is known that the abnormalities vary according to anterior or inferior location of acute myocardial infarction, the relationship with right ventricular acute myocardial infarction is not clear. The ...
Blouin D - - 2001
STUDY OBJECTIVE: The American Heart Association protocols for use of automated external defibrillators (AEDs) recommend that a rhythm analysis be done immediately after each defibrillation attempt. However, shock is often followed by electrical silence or marginally organized electrical activity before ventricular fibrillation (VF) or ventricular tachycardia (VT) recurs. The optimal ...
Wathen M S - - 2001
BACKGROUND: Implantable cardioverter-defibrillators (ICDs) can terminate some ventricular tachycardias (VTs) painlessly with antitachycardia pacing (ATP). ATP has not routinely been applied for VT >188 bpm because of concerns about efficacy, risk of acceleration, and delay of definitive shock therapy. This prospective, multicenter study evaluated the efficacy of empirical ATP to ...
Soejima K - - 2001
BACKGROUND: Extensive lines of radiofrequency (RF) lesions through infarct (MI) can ablate multiple and unstable ventricular tachycardias (VTs). Methods for guiding ablation that minimize unnecessary RF applications are needed. This study assesses the feasibility of guiding RF line placement by mapping to identify a reentry circuit isthmus. METHODS AND RESULTS: ...
Mezaki T - - 2001
Monomorphic ventricular tachycardia (VT) developed in two patients with cardiac sarcoidosis. Before treatment with prednisolone, technetium or gallium scintigram revealed abnormal accumulation in the heart and bilateral hilar lymph nodes, but programmed electrical stimulation failed to induce VT in either case. Prednisolone was administered and the abnormal accumulation of the ...
Tada H - - 2001
The present study investigated the incidence and ECG characteristics of ventricular tachycardias (VTs) originating from the left ventricular (LV) epicardium. Thirty-one consecutive patients with VT or premature ventricular contraction originating from the outflow tract (OT-VT) underwent catheter ablation. Twenty-one OT-VTs were ablated from the endocardium in the right ventricular (RV) ...
Korhonen P - - 2001
The aim of this study was to investigate if magnetocardiographic (MCG) analysis of cardiac micropotentials within the QRS complex can identity patients prone to ventricular arrhythmias, and to compare it to MCG time-domain, late-field analysis. The study population consisted of 136 patients with remote MI, 53 with and 83 without ...
Leder U - - 2001
INTRODUCTION: Late potentials (LP) are markers of arrhythmogenic events after myocardial infarction (MI). The localization of LP sources would help to identify arrhythmogenic myocardium. The purpose of this study was to localize these LP sources from non-invasive body surface mapping data. METHODS AND RESULTS: Six patients were investigated with cardiac ...
Kondo N - - 2001
Ventricular tachyarrhythmia (VT) is an independent risk factor for an increased overall mortality in patients with impaired left ventricular (LV) function, but there is not an established noninvasive tool to detect such patients. The present study aimed to clarify the most useful noninvasive approach for identification of patients with moderately ...
Theuns D - - 2001
AIM: Inappropriate therapy, due to poor discrimination of supraventricular tachycardia (SVT) from ventricular tachycardia (VT) remains a major problem in patients with an implantable cardioverter defibrillator (ICD). Theoretically, the addition of atrial sensing in discrimination algorithms should improve this differentiation. The aim of the study is to evaluate the performance ...
van Dessel P F - - 2001
INTRODUCTION: The exit site and central common pathway of slow conduction are preferred sites to guide radiofrequency ablation of postinfarction ventricular tachycardia (VT). Both require inducibility of VT. In addition, their low amplitude hampers direct recording of potentials generated by activation in pathways of slow conduction. We hypothesized that pace ...
Lee M H - - 2001
Whether or not the excitation-contraction (E-C) uncoupler diacetyl monoxime (DAM) and cytochalacin D (Cyto D) alter the ventricular fibrillation (VF) activation patterns is unclear. We recorded single cell action potentials and performed optical mapping in isolated perfused swine right ventricles (RV) at different concentrations of DAM and Cyto D. Increasing ...
Yano K - - 2001
Idiopathic ventricular tachycardia (VT) has been considered to be amenable to radiofrequency catheter ablation guided by Purkinje potentials. However, there appear to be various types of reentrant circuits associated with this VT deduced from the results of the successful radiofrequency catheter ablation cases. We describe in this report a patient ...
Hamano K K First Department of Internal Medicine, Nara Medical University , 840 Shijo, Kashihara, Nara 630-0183 , - - 2001
Abstract We treated a 17-year-old woman who had systemic lupus erythematosus (SLE) complicated by central retinal vein occlusion (CRVO) and bilateral cerebellar infarction in the absence of demonstrable antiphospholipid antibodies. General fatigue, diffuse polyarthralgia, malar rash, and fever had developed during the 2 weeks preceding admission. The patient was diagnosed ...
Samie F H - - 2001
Reentrant ventricular tachycardia (VT) is the most common sustained arrhythmia leading to ventricular fibrillation (VF). However, despite more than a century of research, the mechanism(s) of the conversion from reentrant VT to VF have not been elucidated. Based on their different electrocardiographic appearance, reentrant VT and VF have traditionally been ...
Matsuyama T - - 2001
An implantable cardioverter defibrillator (ICD) was used in a 62-year-old man with dilated cardiomyopathy (DCM) because of hemodynamically intolerable ventricular tachycardia (VT). Amiodarone was administered after a second episode of ICD discharge. Three weeks later, incessant VT appeared, and DC discharge failed to terminate it. Microvolt T wave alternans (TWA), ...
Hongxuan Z - - 2001
Ventricular fibrillation (VF) is one of the most serious malignant arrhythmias usually resulting from immediate degeneration of ventricular tachycardia (VT). In order to analyse the nonlinear dynamics of the cardiac micro-mechanism under VT and VT rhythm, at the cellular level, myocardial cell action potentials are investigated under different rhythm, normal ...
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 ...
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