Biomedical subjects
Publications and source records attributed to S Saksena.
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The goal of radiofrequency catheter ablation and the criterion for efficacy is the elimination of arrhythmogenic myocardium. The application of radiofrequency current in the heart clearly results in lower morbidity and mortality rates than thoracic and cardiac surgical procedures in general, and comparisons of therapy with radiofrequency catheter ablation and therapy with thoracic and cardiac surgical procedures in randomized clinical trials is unwarranted. Trials of radiofrequency catheter ablation versus medical or implantable cardioverter-defibrillator therapy may be indicated in certain conditions, such as ventricular tachycardia associated with coronary artery disease. Randomized trials are recommended for new and radical departures in technology that aim to accomplish the same goals as radiofrequency catheter ablation. Surveillance using registries and/or databases is necessary in the assessment of long-term safety and efficacy.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The goal of radiofrequency catheter ablation and the criterion for efficacy is the elimination of arrhythmogenic myocardium. The application of radiofrequency current in the heart clearly results in lower morbidity and mortality rates than thoracic and cardiac surgical procedures in general, and comparisons of therapy with radiofrequency catheter ablation and therapy with thoracic and cardiac surgical procedures in randomized clinical trials are unwarranted. Trials of radiofrequency catheter ablation versus medical or implantable cardioverter defibrillator therapy may be indicated in certain conditions, such as ventricular tachycardia associated with coronary artery disease. Randomized trials are recommended for new and radical departures in technology that aim to accomplish the same goals as radiofrequency catheter ablation. Surveillance using registries and/or databases is necessary in the assessment of long-term safety and efficacy.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Technologic development of implantable cardioverter defibrillators (ICDs) is now in an exponential growth phase, and many new concepts are being examined. Major innovations have occurred in pulse generators and in lead systems. This may increase ICD use for primary and secondary prevention of sudden cardiac death. Pulse generators now include hybrid pacemaker-defibrillators. Clinical data suggest a need for demand pacing in primary and secondary prevention applications, with antitachycardia pacing being most valuable in the latter group. Atrial leads will allow dual chamber sensing, pacing, and defibrillation. Low energy cardioversion with biphasic shocks can enhance shock efficacy in rapid monomorphic ventricular tachycardia and flutter. Modifications of lead design, biphasic shock waveforms, and optimal thoracic electrode location in axillary or pectoral regions will permit lower energy defibrillation and smaller pulse generators with lower maximum energy outputs of < or = 25 joules. Dual chamber sensing will improve detection of atrial flutter or fibrillation. Minimum data storage requirements for tachycardia events in ICDs still need to be defined. Intracardiac electrogram analysis is still in evolution, and better analytic methods are awaited. Lead system development is likely to support generic pacing and defibrillation catheter electrodes for atrial and ventricular application. Advances in thoracic electrode design are in progress, and a variety of intercostal electrodes are being tested. Improvements in lead design with further impact on defibrillation energy requirements have the potential to permit generator miniaturization. Significant technologic improvements in ICD devices are imminent and should improve clinical results, patient safety, and quality of life.
Despite substantial progress in the management of ischemic heart disease and congestive heart failure, long-term mortality rates as a result of sudden cardiac death in such patients remain significant. Risk stratification that uses a combination of several predictors of clinical outcome has improved our ability to identify persons at high risk for future arrhythmic events. beta-Blockers and amiodarone are effective in primary prevention of sudden death in selected populations. In view of the impressive reduction in sudden death rates by implantable cardioverter defibrillators (ICDs) in patients with a history of cardiac arrest, prophylactic implantation may also be beneficial. The best way to treat these patients is not known. Three ongoing controlled clinical trials have been designed for drugs, ICDs, or both and will provide answers about whether prophylactic antiarrhythmic intervention with ICDs improves survival and whether device therapy is superior to pharmacologic treatment. Brief reports on these clinical trials are discussed in this review.
Implantable cardioverter defibrillators (ICDs) are now widely used for the secondary prevention of sudden cardiac death and are being offered as a primary preventive therapy. This technology has potential for significant fiscal impact on health care budgets. Technologic innovation will result in more complex devices that are more effective and better accepted by patients and physicians. The clinical impact of these devices will be predicated, in part, by absolute survival benefits but also by their relative advantages over alternative therapies in terms of survival, safety, morbidity, quality of life, and cost. The impact on public health will depend on the effectiveness of screening methods for identification of populations likely to benefit from primary prevention. Risk stratification algorithms are now being tested in several ongoing clinical trials. Dilution of benefit by competing illnesses may occur to different extents in individual patient populations. The economic impact is predicated on the future cost of ICD systems, limitation of hospitalization costs associated with this therapy, and accurate prospective stratification in primary prevention populations. Cost efficacy analyses and quality of life assessment in ongoing and future clinical trials are essential to the development of this therapy and its diffusion into different health care systems. Achievement of clinical benefits, functional independence, and a return to gainful employment by patients will be important determinants of the support lent by health care systems to the dissemination of this therapy.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.