I need to find out from Wiki what a defibrillator eventhough I have vaguely heard about it. I know that heart patients sometime need it because it helps to 'jolt' their heart to pump. Wiki explained it as something that helps with life-threatening cardiac arrhythmias.
They also have these small ones for children with heart problems. It is a little machine that one wears and attached to it are two pads that stick to the chest. Well, not everyone wants to come into this situation where they need the machine. But then, if you have a need for it, take a look at the link provided.