Trials have repeatedly shown that most antiarrhythmic drugs are ineffective in reducing arrhythmic mortality. Given the proven utility of the implantable cardioverter defibrillator (ICD) in the prevention of sudden cardiac death secondary to ventricular tachycardia or fibrillation, it is hardly surprising that in health care jurisdictions able to afford such therapy, there has been a major shift away from the use of antiarrhythmic drugs towards the ICD.The aim of the Clinical Approaches to Tachyarryhthmias series is to update the physician, cardiologist, and all those responsible for the the care of patients with cardiac arrhythmias. This volume provides the practising physician with a summary of the current status of ICD therapy, and addresses the functionality and benefits of its use. Epidemiology of potential candidates and prerequisites for ICD therapy are discussed, along with potential indications explored in several studies.