When saving someones life using an AED is a good idea but only if you do it right. You put the pads on the upper right and lower left. You do this because the shock wants to go the ground. The shock comes out of both pads and wants to travel to the other pad. The heart can only take so much current before it shorts out and cannot be revived. The current that passes through the heart of an AED is just enough to get anyones heart going as long as you get there in time. After the shock is administered then the AED monitors the body to see if there are any vibrations and to check the frequency of the waves to see if they are in rhythm, it they are you saved there life, if not do it again.