Despite the introduction of new therapeutic techniques such as radiofrequency ablation and the implantable defibrillator, the classical opposition of monomorphic ventricular tachycardia in apparently normal hearts and that arising from documented cardiac disease remains useful. In the first case, treatment is only symptomatic whereas, in the second, lethal progression to sudden death must be prevented. Generally speaking, in chronic post-infarct situations, betablockers are underused although they have been shown beyond doubt to reduce cardiovascular mortality. This is probably explained by the fear of possible haemodynamic decompensation in patients who often have left ventricular dysfunction. Nevertheless, different randomised studies of the use of betablockers in cardiac failure have reported reduced mortality with no serious side effects. The use of beta-blockers is therefore advisable, and possible inpatients with or without sustained ventricular tachycardia and underlying cardiac disease. In cases at high risk of sudden death, amiodarone may be associated. Recent randomised studies (MADIT, AVID), comparing the use of implantable defibrillators with those of antiarrhythmic therapy, have shown better results with the implantable defibrillator. However, in these studies, only about 10% of patients received betablockers in the antiarrhythmic treatment groups. This factor has introduced some doubt as to the real benefit of implantable defibrillators. Therefore, a randomised study comparing the efficacy of betablockers with amiodarone against implantable defibrillators is desirable in order to determine the respective indications of each of these two therapeutic modalities.