Early defibrillation is the best thing for somebody having a heart attack. The quicker you can get a defibrillator onto somebody, the better the outcome. Standard non-automated defibrillators, like the ones with the paddles you see doctors using on TV, require costly and time consuming training to use, and anybody who doesn’t do it all the time is likely to get rusty pretty quickly. However the particular condition (ventricular fibrillation) that a defibrillator remedies can reliably be detected by a computer. New automated defibrillators decide themselves if the patient needs to be defibrillated, or “shocked.” The machine will not apply a shock under any other situation…i.e. people can’t use them to shock each other for kicks. All the responder needs to do is attach the sticky-pads to the right place on the body (there is a picture on each pad), turn on the machine, and do what the machine tells him to do. One could argue that somebody with no training could do it pretty well; it’s definitely easier to do correctly than the Heimlich Maneuver, and everybody seems to have a pretty good grasp on how to do that. However, the AHA and manufacturers currently require training to qualify to use one. Almost any Red Cross or Emergency Medical course with Basic Life Support training will teach students how to use an Automated External Defibrillator (AED) as well.
The bottom line is that if I were having a heart attack, I’d be OK with somebody with no medical training having access to an AED and just following the instructions that the machine gives. It’s better than being dead. These are rather expensive at the moment — $2000 $3000 — but they are state-of-the art and their price will likely come down as the market expands. My guess: they will soon be as common in public buildings as fire extinguishers are now.