Clinical usefullnes of the late potentials, OT-prolongation and OT:dispersion, T-wave alternans, heartf rekvency and RR-variability and baroreceptor sensitivity as predictors of malignant arrhythmias, was commented. Prerequisite for the induction of malignant ventricular arrhythmias, ventricular tachycardia (VT) and/or ventricular fibrillation (VF), is the coincidence of several factors, as underliving organic heart disease left ventricular function, imbalance of autonomous nervous system, hypokalemia, drugs and ischaemia. Preventive measures include drugs, use of implantab cardioverter defibrillator (ICD) therapy and antiischaemic interventions. All classes of antiarrhythmic drugs, angiotensin converting enzyme inhibitors and statines were elaluat. To investigate the potential effect of ICD therapy compared to antiarrhythmic drug treatment, three prospective studies-AVID, CASH and CIDS have been conducin wich patients with sustained ventricular arrhythmias were randomised to one of these two treatment strategies. Data from these trials provide support for ICD as a superior therapy to antiarrhythmic drugs, to prolong survival in patients meeting the entry criteria. Antiischaemic interventions (PTCA, CABG) can abolish ischaemia as an important trigger of arrhythmia ind tion, but reports concerning the effects of antiiscaemic interventions as preventive measure for arrhythmogenic events are lacking.