The number of people that die from sudden cardiac arrest growing larger and larger every year. Just so you can make an idea, only in America, more people die from sudden cardiac arrest every three days than the people that died in 9/11. Thing is, many of those deaths could be avoided, if local bystanders wouldn't be bystanders, and would instead perform CPR.
This new type of CPR is called Continuous Chest Compression, was developed by Gordon A. Ewy, MD, and Karl Kern, MD; it's a hands only method, no mouth to mouth. You also don't have to be certified to do it, and it's really really easy to learn. It may very well be the thing that saves a life. Just watch this video: