Cardiovascular disease is the most common cause of sudden cardiac arrest, which causes over 60% of adult coronary heart disease deaths. In Europe, the annual incidence of out-of-hospital cardiopulmonary arrests treated by emergency medical systems is 38 per 100 000. Survival from cardiac arrest depends on a sequence of interventions—the Chain of Survival—comprising (1) early recognition and call for help, (2) early cardiopulmonary resuscitation (CPR), (3) early defibrillation, and (4) postresuscitation care. The division between basic life support and advanced life support (ALS) is arbitrary—the resuscitation process is a continuum....