I saw this TV advert from the British Heart Foundation (BHF) featuring Vinnie Jones a few days ago and thought it was simply great. I have been trained in first aid off and on since I was a kid. I'm currently a designated workplace first aider. During the actual training I come away feeling fairly confident about carrying out CPR for suspected heart attacks. Yet as time goes on I get less and less sure, that in an emergency, I would remember the exact sequence of mouth to mouth resuscitation and chest compressions. If I feel this, you can understand why members of the public, who have never been trained, often panic and don't do nothing when they come across someone dying of a cardiac arrest. What the BHT and Vinnie "explain" is just get on and do "Hands-only CPR" in time to the music (ironically) of "Stayin' Alive" by the Bee Gees. It can make a dramatic difference in survival rates if CPR is given promptly. Time is of the essence.
There is a serious side to this. I will declare that my father died of a heart attack in the street of a small town while he was on a long distance walk. The family know that a Police Officer did attend and tried CPR which eventually failed. What we don't know exactly is how long it took for officer to arrive and whether if a passerby had tried "hand-only CPR" earlier there might have been a different outcome.