In my first aid class in a 230V country we were taught: Someone who got an electric shock always needs to visit the emergency room, even if they seem to be fine

In my first aid class in a 230V country we were taught: Someone who got an electric shock always needs to visit the emergency room, even if they seem to be fine. Reason: fibrillation has to be ruled out or stopped. So 230V stops it does not sound right. Whether there is any difference in probability I have no clue.