On Lifehacker, a comment by AnonJr on the Key to CPR is Stayin’ Alive had this video and some great information about something that is simple (but vital) to know about – please share it around.
Somewhere in the vicinity of 33% of those who go into sudden cardiac arrest don’t receive any help even though there are bystanders available to help.
Most either don’t know what to do or are afraid of doing something. Please, if an adult suddenly collapses, call the emergency number (911 in most of the US) and push hard and fast on the chest.
Depending on the study you look at, an adult who suddenly collapses has around 18 to 22 min. worth of oxygen in his system. Circulating that by pushing hard and fast (~100 compressions per min.) can help keep the body sufficiently oxygenated to increase the chance that a defibrillatory shock will work.
More about Hands Only CPR.