Indeed; for that same reason, that is the reason that you don't shock asystole. Many people (like field paramedics) will shock asystole, saying, "What can it hurt?". If it some old man or woman, that is in asystole after a profound parasympathetic discharge while straining on the toilet, and you shock them, you have killed them, when atropine possibly could have saved them.
This is from the ACLS text 2 books ago (before it was in color).