The heart pumps blood to all of the body's organs. If the heart stops functioning (cardiac arrest), blood flow ceases, organs begin to shut down, and within a few minutes the person will die. If cardiac arrest can be detected and treated immediately, serious organ damage, brain damage, or death may be prevented. Cardiac arrest can occur in adults and children. It may happen suddenly in a person who was thought to be healthy. Community-based programs emphasizing activation of emergency medical services (calling 911 in most areas of North America), cardiopulmonary resuscitation (CPR), and rapid defibrillation (correcting an abnormal heart rhythm with an electrical shock from a defibrillator) have raised public awareness about cardiac arrest and its treatment. However, cardiac arrest remains a major cause of death in all parts of the world. The January 4, 2006, issue of JAMA includes an article about the outcome of cardiac arrest in children and in adults.