Key components of a community response to out-of-hospital cardiac arrest.

Out-of-hospital cardiac arrest (OHCA) remains a leading cause of death worldwide, with substantial geographical, ethnic and socioeconomic disparities in outcome. Successful resuscitation efforts depend on the 'chain of survival', which includes immediate recognition of cardiac arrest and activation of the emergency response system, early bystander cardiopulmonary resuscitation (CPR) with an emphasis on chest compressions, rapid defibrillation, basic and advanced emergency medical services and integrated post-cardiac arrest care. Well-orchestrated telecommunicator CPR programmes can improve rates of bystander CPR - a critical link in the chain of survival. High-performance CPR by emergency medical service providers includes minimizing interruptions in chest compressions and ensuring adequate depth of compressions. Developing local, regional and statewide systems with dedicated high-performing cardiac resuscitation centres for post-resuscitation care can substantially improve survival after OHCA. Innovative digital tools for recognizing cardiac arrest where and when it occurs, notifying potential citizen rescuers and providing automated external defibrillators at the scene hold the promise of improving survival after OHCA. Improved implementation of the chain of survival can save thousands of lives each year.