Hi Mark

I would start by talking to the individual and asking them whether they see any need to treat them differently to any other security guard.

Then, do some research Implantable cardioverter defibrillator (ICD) | BHF

..and may be seek a medical opinion as to whether there are any extra things you need to do, or limitations on what they can do.

Might well be that the implant has in effect dealt with a problem that you might not have known about. Lots of people have lived and worked without any real problems with pacemakers fitted for decades. This seems to be a variant on the same principle.

P

If he's a security guard, he might not have too much exposure to large electromagnetic fields, from things like large motors, magnets, electricity supplies, induction heaters etc. I guess it depends on your working environment and what his job role entails. For sure, EMF's of reasonable strength will have an effect on implanted and bodily worn medical devices (can have the ability to make them stop functioning), so maybe that could be part of your RA?