ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Data are slowly accumulating regarding the possible benefits and appropriate uses of permanent cardiac pacing in a variety of pathophysiologic states or syndromes other than the broad categories and indications of sinus node dysfunction and atrioventricular block. The subjective and physiologic indications for pacing in these disorders are not symptomatic bradycardia or fulfillment of previously accepted criteria for antibradycardia pacing, and pacing is not the first or only therapy used. Therefore, individual patient evaluation, often including documentation of the response to temporary pacing therapy prior to implantation of a permanent device, is helpful and may be necessary. Controversy regarding the data available, and expanding clinical use of permanent cardiac pacing in a number of these conditions or syndromes, remains.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Significant advances in the basic science of implantable cardioverter- defibrillator therapy have led to improvements in defibrillation waveforms and in capacitor technology. Nonthoracotomy devices with biphasic waveforms can be implanted with a near 100% success rate. Although fewer patients with implantable cardioverter-defibrillators are being treated with concomitant antiarrhythmic drug therapy, sotalol appears to decrease the defibrillation threshold. Controversy still exists over the optimal design for defibrillator sensing leads. Tachyarrhythmia detection enhancements increase specificity for sensing ventricular tachycardia but may risk undersensing. A variety of subsets of patients receiving implantable cardioverter-defibrillators have been identified; patients presenting with ventricular fibrillation appear to have the most unfavorable prognosis. Controversy exists as to the true impact of implantable cardioverter-defibrillator therapy on subsequent survival. Randomized clinical trials such as AVID (Antiarrhythmics Versus Implantable Defibrillators) are designed to determine the true benefits of implantable cardioverter- defibrillators and may lead to expanded indications.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Recurrent episodes of unexplained syncope are among the most frequent of complaints referred to physicians for evaluation. Traditional methods of evaluation were both time consuming and expensive and left many patients without a diagnosis. Although neurocardiogenically mediated episodes of hypotension and bradycardia were felt to be a common cause of syncope, this was traditionally a diagnosis of exclusion. The emergence of head-upright tilt-table testing has provided a valuable method for identifying individuals predisposed to neurocardiogenic syncope and has also allowed for a better understanding of this phenomena. This article reviews the pathophysiology of neurocardiogenic syncope, the use of head-upright tilt-table testing in its diagnosis, and the potential therapies used to prevent recurrences.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

During the past half decade, significant insight into the clinical, electrocardiographic, and genetic features of the congenital long QT syndromes has emerged. Based on this foundation, recent linkage analysis studies have demonstrated the genetic heterogeneity of the Romano-Ward long QT syndrome and led to the discovery of two of the four (or more) responsible genes. Further functional characterization of these two genes, theHERGpotassium channel and theSCN5Avoltage-gated cardiac sodium channel, as well as the identification and characterization of the other long QT syndrome genes, may allow improved diagnosis and therapy for these disorders. Furthermore, the increased understanding of myocardial repolarization that is gained from characterization of these genes may lead to improved treatment for other ventricular arrhythmias, including those related to potassium-channel blockade, central nervous system insult, and, possibly, myocardial infarction.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Acoustic quantification, a new ultrasound technique, provides a more direct assessment of the health of the myocardium than conventional echocardiography. Through software enhancements, acoustic quantification can characterize the myocardium as viable or nonviable, automatically track the endocardium throughout the cardiac cycle, and show myocardial perfusion defects when used with contrast enhancement. Thus, this technique shows promise in linking perfusion, viability, and global function in adults and perhaps in children.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Techniques of transcatheter device placement for treatment of pediatric congenital heart disease have developed substantially since their introduction 20 years ago. Patent ductus arteriosus occlusion can be accomplished by umbrella deployment or coil placement. Intracardiac defects can be closed with umbrella or buttoned devices. Stenoses of vessels or conduits that are only temporarily relieved with balloon dilation can be effectively expanded with intravascular stents. Recent procedural modifications have been introduced in an attempt to minimize the size of the delivery sheath and reduce complications that can arise from device embolization. Transcatheter device placement can be an important adjunct to surgery for correction or palliation of congenital heart lesions.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID