In Europe, 40% of all deaths of individuals who are 25-74 years of age are caused by cardiovascular disease. Cardiac disease is the underlying cause in two-thirds of out-of-hospital sudden deaths. The 28-day case fatality rate for the combined population of out-of-hospital coronary artery disease deaths and hospitalized acute myocardial infarction patients is approximately 50% in 29 of the regions included in the World Health Organization (WHO) Monitoring Trends and Determinants in Cardiovascular Disease registry. Of 14,065 patients included in the Swedish Cardiac Arrest Registry, resuscitation procedures were started in 10,966 patients. The remaining 3,099 were considered definitely dead; 70% were witnessed, cardiac arrests and 32.3% had been given bystander cardiopulmonary resuscitation (CPR). The incidence of ventricular tachycardia (VT)/ventricular fibrillation (VF) in all patients was 43%, in witnessed cases 54%, and in nonwitnessed cases, 31%. The initial incidence of VT/VF was calculated to be approximately 60% in the whole population and 80-85% in those with probable cardiac disease. Survival to 1 month was 5.0% in the total population, 9.5% for those with VT/VF on the first electrocardiogram compared with 1.6% for those not in VT/VF. Survival rate was also calculated in relation to delay time to first defibrillation. Survival was 50% when defibrillation was performed immediately and decreased gradually to 0% for those with a delay time of 20 minutes. The survival rate after bystander CPR was 2.6-fold higher than the rate for those where no treatment was given until the ambulance arrived.