Out-of-hospital cardiac arrest (OHCA) is a condition characterised by unexpected cardiovascular collapse and is a leading cause of death. Patient resuscitation is challenging and requires a coordinated set of rescuer actions termed the “Chain of Survival.”

The links in the "Chain of Survival" are

  • immediate recognition of cardiac arrest and activation of the emergency response system
  • early cardiopulmonary resuscitation (CPR)
  • rapid defibrillation
  • effective advanced life support
  • integrated post–cardiac arrest care

Efforts that can improve early recognition of OHCA and increase bystander CPR are likely to improve survival.