American heart journal
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The role and success rate of catheter ablation for monomorphic ventricular tachycardia (VT) depend on the mechanism and origin of the tachycardia (i.e., myocardial versus His-Purkinje system) and whether it occurs in the presence or absence of structural heart diseases. For sustained bundle-branch reentry, a form of VT associated with structural heart disease, radiofrequency catheter ablation of the right bundle-branch can be performed readily and is highly successful in eliminating this arrhythmia. ⋯ Radiofrequency catheter ablation may be the treatment of choice in patients with VT and no apparent structural heart disease; this is especially true for young patients who would otherwise require long-life antiarrhythmic therapy. Success rates between 75% and 100% have been reported, especially when the origin is in the right ventricular outflow tract.
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American heart journal · Apr 1994
Complications of pacemaker-defibrillator devices: diagnosis and management.
Treatment of resuscitated patients with implantable cardioverter defibrillators has become increasingly more common as a method for the prevention of sudden cardiac death. Major complications such as perioperative death (incidence 2% to 8%), infection (2% to 11%); and lead-related problems (3% to 27%) have been described in previous trials. In our experience with 140 patients, problems were related to leads (n = 11), the device (n = 2), pacing (n = 1), sensing (n = 13), and defibrillation function (n = 5). ⋯ Surgical management (predominantly for the major problems) was used in 31 (48%) patients, drug treatment in 25 (39%), and reprogramming of the device in 24 (38%) patients. All of these problems can result in an increase in mortality rates. This article provides an overview of the complications of cardioverter defibrillator treatment and is based on both published data and our series.
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American heart journal · Apr 1994
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialImplantable cardioverter defibrillator compared with antiarrhythmic drug treatment in cardiac arrest survivors (the Cardiac Arrest Study Hamburg).
In 1987, the Cardiac Arrest Study Hamburg (CASH), a prospective, multicenter, randomized controlled study, was started in survivors of sudden cardiac death resulting from documented ventricular tachyarrhythmias. Through December 1991, 230 survivors (46 women, 184 men; mean age 57 +/- 11 years) of cardiac arrest caused by ventricular tachyarrhythmias were randomly assigned to receive either oral propafenone (56 patients), amiodarone (56 patients), or metoprolol (59 patients) or to have an implantable defibrillator (59 patients) without concomitant antiarrhythmic drugs. The primary endpoint of the study was total mortality. ⋯ This article presents preliminary results of the comparison of implantable defibrillator therapy with propafenone therapy. A significantly higher incidence of total mortality, sudden death (12%), and cardiac arrest recurrence or sudden death (23%) was found in the propafenone group compared with the implantable defibrillator-treated patients (0%, p < 0.05). It was concluded that, in survivors of cardiac arrest, propafenone treatment is less effective than implantable defibrillator treatment.
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American heart journal · Apr 1994
ReviewConsiderations for ventricular fibrillation detection by implantable cardioverter defibrillators.
Implantable cardioverter defibrillator detection of ventricular fibrillation is inherently a complicated process. Nevertheless, there is a clinical imperative that ventricular fibrillation be detected with 100% sensitivity. ⋯ In this review we look in generic terms at the different lead and detection systems available and the effect of these systems on both undersensing and oversensing of ventricular fibrillation. In addition, several clinical and programming issues that affect sensitivity and specificity of ventricular fibrillation detection are reviewed.
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American heart journal · Apr 1994
ReviewThe role of pacing for the management of neurally mediated syncope: carotid sinus syndrome and vasovagal syncope.
The role of permanent cardiac pacing for the management of neurocardiogenic syncope is controversial; however, it does have a secondary role in appropriately selected individuals. Neurocardiogenic syncope includes vaso-vagal and enhanced antagonism of sympathetic-parasympathetic mechanisms. Differentiation of the so-called cardiac inhibitory, vasodepressor, and mixed forms of these disorders is frequently misleading when establishment of effective treatment strategies is attempted. ⋯ Syncopal patients with carotid sinus hypersensitivity or vasovagal responses that include marked bradycardia and loss of atrioventricular synchrony can be supported by dual-chamber cardiac pacing in combination with other therapeutic interventions that diminish the severity of the reflex response. The conditions of patients with carotid sinus syndrome and carotid sinus hypersensitivity are frequently improved with cardiac pacing, and the conditions of elderly patients with vasovagal syncope are commonly improved with artificial pacing. The classic younger patient with malignant vasovagal syncope derives less benefit from artificial pacing; however, in carefully selected persons dual-chamber pacing combined with drug therapy and education decreases syncopal episodes and permits a return to normal activities.