CPR keeps a heart quivering. Victims are more often found still in "V-fib" by medics when a bystander performs CPR.
Strangers will come to the rescue. Victims are four times more likely to get bystander CPR outside the home than inside.
Quick action is the key. The faster a bystander starts giving CPR the more likely the victim is to survive.
From this article:
http://www.usatoday.com/news/nation/ems-main.htm
Powerful and important reading!!!