NdFeB magnets vs. pacemakers

NdFeB magnets, being the strongest known permanent magnets, are warned to be a hazard to people with pacemakers. I would expect a magnet could disrupt a
device that uses magnetic or certain static fields for operation, such as computer hard drives, magnetic recording media, CRT screens, etc. It can also mechanically damage some things, like bending the fragile mask inside a CRT tube.
But I have found no effect of such a magnet on an electric circuit.
So my question, what is in a pacemaker that would make it susceptible to a strong magnetic field like this?
Yeah, this is probably more of a biomedical engineering question than just an electrical engineering question. But sci.engr.biomed seems to be dead (not counting spam).
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     snipped-for-privacy@ipal.net writes:

A couple of things I might guess at...
The obvious risk of something metalic/magnetic being displaced. I don't know if there are any such susceptable parts in a pacemaker.
The other thing is that a magnetic field will exert a force on a moving electron, i.e. signals travelling along nerves. At some point, this will disrupt the nerve signalling. A pacemaker is interfacing with nerve signals, both reading and generating them.
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writes:

Also, further guessing, a moving magnet creates a changing magnetic field, a changing electric field, and flux linkage and voltages/currents in circuits.
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