Bystander cardiopulmonary resuscitation (CPR) is chest compression and ventilations provided by someone not on the emergency response team. A victim or cardiac arrest is almost 4 times more likely to survive when receiving bystander CPR. However, despite various attempts to improve bystander rates they have remained low, not exceeding 15% in Ontario. It has been shown that since the ambulance dispatch centres in Ontario implemented dispatch-assisted CPR instructions (given to callers while emergency vehicles were on the way), there was a significant increase in use.