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Wang Y - - 1999
Increasing defibrillation efficacy by lowering the defibrillation threshold (DFT) is an important goal in positioning implantable cardioverter-defibrillator electrodes. Clinically, the DFT is difficult to estimate noninvasively. It has been suggested that the DFT relates to the myocardial voltage gradient distribution, but this relation has not been quantitatively demonstrated. We analyzed ...
Kyle J M - - 1999
Fatalities during sports participation are usually cardiac in origin. Sudden Cardiac Arrest (SCA) from ventricular fibrillation has been reported in several sporting venues over the last decade. Successful treatment of stadium SCA requires a rapid response team equipped with defibrillator capabilities. The use of automated external defibrillators (AED) by responders ...
Peters R W - - 1999
Previous studies have shown that life-threatening ventricular arrhythmias display both circadian and septadian (day of the week) periodicity. We hypothesized that assessing the relation between these circadian and septadian rhythms may provide important pathophysiologic information about the mechanism of sudden cardiac death. Using the database from a population of 683 ...
Dhala A - - 1999
Because of the high incidence of heart disease in the elderly, ventricular tachyarrhythmias are not infrequent. Determining the nature and extent of the underlying heart disease and identifying precipitating causes is required prior to instituting long-term therapy. Recent studies suggest that for hemodynamically unstable ventricular tachyarrhythmias, mortality is lower with ...
Geelen P - - 1999
In patients with sustained ventricular tachyarrhythmias and myocardial ischemia due to multivessel coronary artery disease, it remains unclear whether revascularization is enough to control the arrhythmias or whether additional implantation of a defibrillator is indicated. We therefore reviewed our clinical strategy of performing both bypass surgery and implantation of a ...
Cooklin M - - 1999
OBJECTIVES: The purpose of this study was to compare transvenous atrial defibrillation thresholds with lead configurations consisting of an active left pectoral electrode and either single or dual transvenous coils. BACKGROUND: Low atrial defibrillation thresholds are achieved using complex lead systems including coils in the coronary sinus. However, the efficacy ...
Le Franc P - - 1999
Despite a growing number of implantable cardioverter-defibrillator (ICD) lead removal indications, there is no consensus about extraction techniques. We applied our experience of pacemaker lead removal to ICD leads using a superior approach with a standard extractor kit, and an inferior approach with a lasso, or a surgical extraction. Fifteen ...
Birgersdotter-Green U - - 1999
BACKGROUND: The upper limit of vulnerability (ULV) is the stimulus strength above which ventricular fibrillation cannot be induced, even when the stimulus occurs during the vulnerable period of the cardiac cycle. Determination of ULV using T-wave shocks during ventricular pacing has been shown to closely correlate with the defibrillation threshold ...
Shohat-Zabarski R - - 1999
A 58-year-old patient with dilated cardiomyopathy underwent implantable cardioverter defibrillator (ICD) implantation. The postoperative course was complicated by perforation of the right ventricular free wall by the active fixation transvenous ICD lead. The type of ICD lead and the type of organic heart disease are apparently important risk factors for ...
Fogoros R N - - 1999
Evidence from recent randomized clinical trials now strongly supports the use of the implantable defibrillator, as treatment of first choice, in patients who have experienced symptomatic, sustained ventricular tachyarrhythmias. Little or no controversy remains on this question, either among physicians or third-party players. The evidence-based use of the defibrillator as ...
Walker S - - 1999
We report a case of fully transvenous single-unit biventricular implantable cardioverter defibrillator (ICD) use in a 43-year-old woman with a manifesting carrier form of muscular dystrophy (Emery-Dreifuss syndrome). The indication for biventricular ICD use was progressive heart failure with ventricular arrhythmia, permanent atrial fibrillation and previous VVIR pacemaker insertion. Single-unit ...
Wilbur S L - - 1999
Over the past few years, remarkable advances in the treatment of ventricular tachycardia, ventricular fibrillation, and sudden cardiac death have occurred. One of the most significant treatment modalities has been the addition of the implantable cardioverter-defibrillator (ICD). Because of the rapidly expanding indications for ICD therapy, it is common for ...
Alexander R E - - 1999
BACKGROUND: More than 350,000 adult Americans die each year of sudden cardiac arrest, or SCA. The event is unpredictable and can occur in patients with no history of cardiac disease or cardiac symptoms. Drugs and cardiopulmonary resuscitation, or CPR, save only a small percentage of victims. The necessary response is ...
Lerman RD - - 1999
Survivors of an episode of out-of-hospital ventricular fibrillation (not due to a reversible cause) or hemodynamically significant sustained ventricular tachycardia should in most cases receive an implantable cardioverter defibrillator (ICD) rather than antiarrhythmic drug therapy. A number of recently published clinical trials (summarized later) point to improved survival with ICD ...
Sticherling C - - 1999
AIMS: The need for physiological pacing and for improving the ability to discriminate atrial from ventricular tachyarrhythmias has prompted the development of dual chamber implantable cardioverter/defibrillators (ICDs). METHODS: Fifty-two patients were implanted with a newly developed dual-chamber ICD providing rate-responsive physiological pacing (Ventak AV II DR). The device possesses two ...
Yamanouchi Y - - 1999
INTRODUCTION: A single lead active can configuration has been widely used in patients with life-threatening ventricular arrhythmias. Occasionally, however, such a defibrillation lead configuration may not achieve adequate defibrillation threshold (DFT). The purpose of this study was to determine whether addition of a left ventricular (LV) lead can improve defibrillation ...
Fotuhi P C - - 1999
Today, transthoracic and intracardiac defibrillation offer a well-accepted and widely used form of therapy for patients with life-threatening ventricular arrhythmias. Despite the wide clinical use of defibrillators, the mechanisms by which an electrical shock halts fibrillation are still not completely understood. During a shock, different amounts of current flow through ...
Heisel A - - 1999
Atrial fibrillation (AF) is an extremely common arrhythmia seen in clinical practice. Because of the limited efficacy of traditional therapeutic strategies to restore and maintain normal sinus rhythm, several nonpharmacologic options have evolved. The promising results achieved with internal atrial defibrillation have facilitated the development of an implantable atrial defibrilator. ...
Böcker D - - 1999
Ventricular tachycardia and ventricular fibrillation account for a substantial proportion of all deaths in patients with heart failure. Of currently available therapies, amiodarone and the implantable cardioverter defibrillator (ICD) appear to have the greatest potential to decrease sudden death in heart failure. In this article, the presently available information on ...
Amaya S C - - 1999
Ultrasonography in the emergency department is being used for many purposes, including the evaluation of patients with cardiac arrest. Ultrasound testing has been shown to be useful in such patients in determining the presence of true electromechanical dissociation and pericardial effusions. We report a case of ventricular fibrillation identified by ...
Tachibana H - - 1999
The purpose of this study was to establish an animal model in which ventricular fibrillation (VF) can be induced reproducibly and defibrillation can be accomplished repeatedly. The left anterior descending artery (LAD) was cannulated and perfused with blood from the carotid artery in eleven open-chest dogs. Electrodes of the internal ...
Wolk R - - 1999
Moxonidine has been shown to be antiarrhythmic during ischaemia in vivo. This study aimed to investigate its electrophysiological effects in isolated working rabbit hearts in vitro. Monophasic action potential duration, effective refractory period and conduction delay were measured at three ventricular sites. The hearts were treated before and during ischaemia ...
Dhala A - - 1999
Because of the high incidence of heart disease in the elderly, ventricular tachyarrhythmias are not infrequent. Determining the nature and extent of the underlying heart disease and identifying precipitating causes is required prior to instituting long-term therapy. Recent studies suggest that for hemodynamically unstable ventricular tachyarrhythmias, mortality is lower with ...
Chinushi M - - 1999
An implantable cardioverter defibrillator (ICD) was implanted in a patient with ventricular fibrillation (VF) related to old myocardial infarction. During VF, amplitude of ventricular activation was small, and the ventricular sensitivity at 1.2 mV failed to detect several small ventricular activations. When the sensitivity was changed to 0.3 mV, both ...
Khoshnevis G R - - 1999
The benefit of defibrillator therapy has been well established for patients with LV dysfunction (ejection fraction less than 35%), coronary artery disease, NSVT, and inducible and nonsuppressible ventricular tachycardia. Implantable cardioverter-defibrillator therapy is also indicated for all CHF patients in NYHA functional classes I, II, and III who present with ...
Smith W M - - 1999
Ventricular fibrillation, a loss of synchronous electrical activity in the heart which leads to hemodynamic collapse, is a leading cause of death. Because of the devastating personal and societal effects of this phenomenon, the automatic cardioverter-defibrillator has been developed for automatic detection and termination of the arrhythmia and is in ...
Pitkin A - - 1999
Defibrillation plays a crucial role in the resuscitation of patients from acute life-threatening cardiac dysrhythmias causing cardiac arrest. Concerns over safety and function of defibrillators under pressure have so far prevented their routine use in clinical hyperbaric chambers. Increasing numbers of unstable and critically ill patients are being treated in ...
Morgan J M - - 1998
We report a single center's preliminary clinical experience of the Sentinel (Angeion, Minneapolis, MN) implantable cardioverter defibrillator (ICD), which employs novel technologies that offer the potential for significant reduction in ICD size. Thirty-three patients have received Sentinel ICDs with a mean follow-up of 450 (range 150-1023) days. Device shock therapy ...
Kühlkamp V - - 1998
Even with the use of biphasic shocks, up to 5% of patients need an additional subcutaneous lead to obtain a defibrillation safety margin of at least 10 J. The number of patients requiring additional subcutaneous leads may even increase, because recent generation devices have a < 34 J maximum output ...
Cantwell J D - - 1998
At first glance, the idea of having automatic external defibrillators (AEDs) at sports events may seem curious, since spectator sports are the domain of young, healthy athletes. Yet athletes are not entirely free of cardiac risk. More important, there are many other people at sports events (officials, coaches, fans) who ...
Walcott G P - - 1998
BACKGROUND: Recently, interest has arisen in using biphasic waveforms for external defibrillation. Little work has been done, however, in measuring transthoracic defibrillation efficacy after long periods of ventricular fibrillation. In protocol 1, we compared the efficacy of a quasi-sinusoidal biphasic waveform (QSBW), a truncated exponential biphasic waveform (TEBW), and a ...
Sandstedt B - - 1998
A new, thinner (10 Fr) and more flexible, single-pass transvenous endocardial ICD lead, Endotak DSP, was compared with a conventional lead, Endotak C, as a control in a prospective randomized multicenter study in combination with a nonactive can ICD. A total of 123 patients were enrolled, 55 of whom received ...
Gliner B E - - 1998
Few victims of sudden cardiac arrest survive. A new generation of automatic external defibrillators (AEDs), smaller, lighter, easier to use, and less costly, makes the goal of widespread AED deployment and early defibrillation feasible. A low-energy impedance-compensating biphasic waveform allows AED device characteristics more suitable to the goal of early ...
Epstein A E AE Division of Cardiovascular Disease, Department of Medicine, University of Alabama, Birmingham, AL, USA - - 1998
Although the effects of epicardial implantable cardioverter-defibrillator (ICD) leads on underlying cardiac tissue have been reported, the gross and microscopic changes associated with endocardial ICD leads are less well described. This study describes the gross and microscopic changes associated with endocardial ICD leads in humans. The hearts from 8 patients ...
Winter J - - 1998
OBJECTIVES: The effect of implantable cardioverter/defibrillator (ICD) lead placement in the right ventricle (RV) on defibrillation efficacy has not been thoroughly investigated. Therefore, the goal of this combined experimental and clinical study was to evaluate the effect of a septal and a non-septal position of the right ventricular endocardial spring ...
Pacifico A - - 1998
The Jewel 7219D was the first non-thoracotomy implantable cardioverter-defibrillator (ICD) with biphasic shock capability small enough to be placed in the prepectoral subcutaneous position. Size reduction of ICDs is desirable, but safety and efficacy of smaller devices must be demonstrated. Outcomes of patients treated with the Jewel 7219D defibrillator (n ...
Kirchhof P F - - 1998
AIMS: To elucidate the mechanism of spontaneous termination of ventricular fibrillation (VF) and to define an indicator of its occurrence, the phase angle, a novel measure to assess synchrony of activation, was evaluated. METHODS AND RESULTS: In 7 isolated rabbit hearts, 7 monophasic action potentials were recorded simultaneously. Ventricular fibrillation ...
Wong G C - - 1998
A 69-year-old man developed an embolus to his right femoral artery 24 h following the insertion of an implantable cardioverter defibrillator (ICD), with multiple shocks administered in the early postoperative period. He had nonobstructive hypertrophic cardiomyopathy with normal left ventricular function and no evidence of left atrial or ventricular thrombus ...
Wolfhard U F - - 1998
Intraoperative testing with several fibrillation/defibrillation episodes (FDEs) is routinely performed during defibrillator implantation. Testing is considered safe even in patients with severe cardiac impairment, provided the recovery timespans and number of FDEs are adapted to the individual patient. Myocardial lactate extraction (MLE) was examined in two testing protocols. In 30 ...
Every N R - - 1998
We defined the proportion of post-myocardial infarction patients who would have been eligible for the Multicenter Automatic Defibrillator Implantation Trial (MADIT) from a population of 94,797 patients with myocardial infarction entered into the Cardiac Arrhythmia Suppression Trial Registry. From this large population, only between 0.3% to 1.7% would have met ...
Natalia Trayanova,Kirill Skouibine,Felipe Aguel,N. ...
The purpose of this paper is to investigate the relationship between cardiac tissue structure, applied electric field and the transmembrane potential induced in the process of defibrillation. It outlines a general understanding of the structural mechanisms that contribute to the outcome of a defibrillation shock. Electric shocks defibrillate by changing ...
Mosesso V N VN - - 1998
OBJECTIVE: To determine the feasibility of police officers providing defibrillation with automated external defibrillators (AEDs) and to assess the effectiveness of this strategy in reducing time to defibrillation of victims of out-of-hospital sudden cardiac arrest. METHODS: This was a prospective, interventional cohort study with historical controls conducted in 7 suburban ...
Jung W - - 1998
INTRODUCTION: Internal atrial defibrillation has been evaluated as an alternative approach to the external technique for more than two decades. Previous studies in animals and humans have shown that internal atrial defibrillation is feasible with relatively low energies. The promising results achieved with internal atrial defibrillation have facilitated the development ...
Strobel J S - - 1998
OBJECTIVES: The purpose of this study was to determine if the defibrillation threshold (DFT) is lower during the first few cycles of ventricular fibrillation (VF) than after 10 s of VF and, if so, if the effect is caused by local or global factors. BACKGROUND: The DFT may be low ...
Santini M - - 1998
Low-energy intra-atrial defibrillation is a new therapeutic option for restoring sinus rhythm in patients with atrial fibrillation (AF). The success rate is quite high when right atrium-coronary sinus or right atrium-pulmonary artery electrode configurations are used, although the former is associated with a slightly lower defibrillation threshold. Several issues regarding ...
Minen G - - 1998
A patient with ischemic dilated cardiomyopathy and history of ventricular fibrillation received an implantable cardioverter defibrillator by the nonthoracotomy approach. Four years later, during elective replacement of an exhausted pulse generator, a superior vena caval thrombotic occlusion with collateral circulation through the azygos and emiazygos vein systems was documented. This ...
Naccarelli G V - - 1998
Multiple trials using antiarrhythmic drugs, pharmacologic therapy, and implantable cardioverter defibrillators have been performed in an attempt to improve survival in patients: (1) postmyocardial infarction; (2) with congestive heart failure, with and without nonsustained ventricular tachycardia; and (3) with sustained ventricular tachycardia and those who have survived an out-of-hospital cardiac ...
Goldberger J J - - 1998
INTRODUCTION: Dedicated bipolar sensing has been suggested to be safer than integrated bipolar sensing due to an increased incidence of failure to redetect ventricular fibrillation after an unsuccessful shock with leads that use integrated bipolar sensing. We compared sensing characteristics during ventricular fibrillation of simultaneously recorded dedicated and integrated bipolar ...
Vogel U - - 1998
A 37-year-old Italian male developed a myocardial infarct with subsequent ventricular fibrillation. He was defibrillated seven times with up to 360 Joules. Thirteen days later the patient died of recurrent myocardial infarct due to thrombotic occlusion of the left circumflex coronary artery. At autopsy, necrosis of the right pectoralis muscle ...
Viskin S - - 1998
Different polymorphic ventricular tachyarrhythmias may cause syncope or cardiac arrest in patients with no heart disease: (1) Catecholamine-sensitive polymorphic ventricular tachycardia (VT) presents during childhood: the hallmark is the reproducible provocation of atrial and polymorphic ventricular arrhythmias during exercise, despite a normal QT. Beta-blockers are the treatment of choice. (2) ...
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