Vader and Life Support

Rating: 9/10 (12 May 2005)

I was wondering. If Vader's life was dependent on his life support system and a few seconds of force lightning messed that up and killed him, then why didn't any of his 'followers' (And I'm sure many wanted to commit regicide on their leader) use the same trick on him. They knew he was on life support (right?), the breathing surely showed some signs, and It wasn't fatigue(Vader doesn't move often) or heavy smoking so they could've killed him if they wanted to, with any source of electrical current? (I'm overdoing it here I know but it's a valid point right?) Your humble opinions (and please make jokes,the subject deserves it';)