strong magnetic fields need to be avoided such as MRI scanners etc, this is probably more to do with the possibility of dislodging pacing wires/distortion of images etc but as to small magnets as on these cases? I wouldn't say with certainty.. modern pacemakers do run off microprocessors according to the manufacturer but without seeing exactly what's in the tin (so to speak) it's an unknown. I would imagine that no one has really done any study into what strength magnet would interfere (through layers of skin/fat and muscle) with a pacemaker... it's an interesting topic but I don't think you'll get any conclusions unless we have a cardiothoracic surgeon in our midst??
