We have just received an electric can opener and it states "not to be used if fitted with a pacemaker" surel this would apply to a vacuum cleaner or any other electric appliance. We understand about tens machine, and similar health machines.
I cannot see any reason why an electric can opener should affect the pacemaker.
I agree, the same principle should apply to other electrical appliances.
My advice would be to either do what the instructions say......OR...what I would do, give it a try and if you do feel dizzy, then walk away.
Is your electric can opener one which uses a large magnet to grip the lid of the can? If so, it might be that magnet (rather than the electric motor, which is common to all electric can openers) which has caused the manufacturers to issue a warning.