I'm currently in the process of working on a Sci-Fi novel and have a question about electricity and nerves. It might be a difficult question, but if anyone has any insight that would be very helpful. The first question is... can a strong enough electric shock give a person heart failure and kill them instantly? Or if not a heart attack... then what would kill them? Second Question is are the nerves in your body currents of electricity? If so, with futuristic technology, would it be possible to assume there would be some way to increase the amount of electricity generated from them? Number three, if I wrote about a weapon in the future (mainly designed for assassination) where a human could have strong currents of electricity planted in tubes in their body (or use what they have in their nerves and amplify it) and could then touch people to give them a shock strong enough to inflict heart failure... would that be believable? It probably all sounds a bit crazy and I bet doesn't make much scientific sense, but if anyone could help me out here, that would be great.