Implantable devices for treating tachyarrhythmias
| Autor: | Timothy Houghton, Gerry Kaye |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2003 |
| Předmět: |
Tachycardia
medicine.medical_specialty Clinical Review Automobile Driving Poison control Ventricular tachycardia Intracardiac injection Cardioverter-Defibrillator Electrocardiography Internal medicine Atrial Fibrillation medicine Humans cardiovascular diseases General Environmental Science business.industry General Engineering Cardiac Pacing Artificial Atrial fibrillation General Medicine Equipment Design medicine.disease Defibrillators Implantable Atrial Flutter Anesthesia Ventricular fibrillation Practice Guidelines as Topic cardiovascular system Cardiology General Earth and Planetary Sciences Supraventricular tachycardia medicine.symptom business |
| Popis: | Pacing treatment for tachycardia control has achieved success, notably in supraventricular tachycardia. Pacing termination for ventricular tachycardia has been more challenging, but an understanding of arrhythmia mechanisms, combined with increasingly sophisticated pacemakers and the ability to deliver intracardiac pacing and shocks, have led to success with implantable cardioverter defibrillators. There are two methods of pace termination. Underdrive pacing was used by early pacemakers to treat supraventricular and ventricular tachycardias. Extrastimuli are introduced at a constant interval, but at a slower rate than the tachycardia, until one arrives during a critical period, terminating the tachycardia. Because of the lack of sensing of the underlying tachycardia, there is a risk of a paced beat falling on the T wave, producing ventricular fibrillation or ventricular tachycardia, or degenerating supraventricular tachycardias to atrial fibrillation. It is also not particularly successful at terminating supraventricular tachycardia or ventricular tachycardia and is no longer used routinely. Changes in implantable cardioverter defibrillators over 10 years (1992-2002). Apart from the marked reduction in size, the implant technique and required hardware have also dramatically improved—from the sternotomy approach with four leads and abdominal implantation to the present two-lead transvenous endocardial approach that is no more invasive than a pacemaker implant Overdrive pacing is more effective for terminating both supraventricular and ventricular tachycardias. It is painless, quick, effective, and associated with low battery drain of the pacemaker. Implantation of devices for terminating supraventricular tachycardias is now rarely required because of the high success rate of radiofrequency ablative procedures (see previous article). Overdrive pacing for ventricular tachycardia is often successful but may cause acceleration or induce ventricular fibrillation. Therefore, any device capable of pace termination of ventricular tachycardia must also have defibrillatory capability. View this table: Mechanisms of arrhythmias Initially, cardioverter defibrillator implantation was a major operation requiring thoracotomy and was associated with 3-5% mortality. … |
| Databáze: | OpenAIRE |
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