Patients resuscitated from ventricular fibrillation or haemodynamically compromising ventricular tachycardias have an unfavourable clinical outcome. Moreover, there is no evidence that the prognosis can be improved by empirical use of antiarrhythmic therapy. Therapy guided by electrophysiological stimulation or long-term ECG identifies a subgroup of patients with a better outcome (in whom arrhythmias are suppressed) and a subgroup with a bad prognosis (in whom arrhythmias are not suppressed). However, this does not say that antiarrhythmic drugs actually improve the outcome. It may simply identify patients with an intrinsically good prognosis, regardless of whether they receive drug treatment. Because retrospective trials have reported that empiric administration of amiodarone provides long-term control in two-thirds or more of patients with refractory ventricular tachyarrhythmias, a direct comparison with other drugs guided by electrophysiological testing or long-term ECG was performed (CASCADE-study). Six-years survival was 41% under amiodarone versus 20% with other drugs. Even those conventionally treated patients, whose inducible arrhythmias were suppressed, had a trend toward a worse prognosis compared to those who were inducible and treated empirically with amiodarone. However, the high recurrence rate of arrhythmic events demonstrates the limitation of any antiarrhythmic drug, irrespective of the drug used and irrespective of whether it is given empirically or in a study.