This main session, chaired by S.G. Priori (Pavia, Italy) and M. Komajda (Paris, France), provided an update on different studies focusing on (prevention of) sudden cardiac death (SCD) in heart failure (HF) patients. First speaker wasJ. Farre (Madrid, Spain), whose talk focused on the epidemiology and mechanisms of SCD in HF patients. The definition ofSCD remains controversial, since many deaths are not witnessed, and without cardiac monitoring the assumption of an underlying arrhythmic cause is speculative. Nevertheless, the overall incidence of SCD in the United States is 1 to 2/1000 per year (0.1 to 0.2%) in the general population. Almost, one-third of all SCDs occur in patients with depressed left ventricular ejection fraction (LVEF,