Note of caution for pacemaker and iPhone 12 users

Pacemakers include a magnetic switch to shut them down. Placing an iPhone 12 over the pacemaker was shown to cause shutdowns. Thus, say, carrying an iPhone 12 in a shirt pocket could cause pacemaker shutdown.


My first reaction was: “That can’t be true.”

But apparently it is - and it does make sense… Surely something to be aware of if somebody has a pacemaker…

Not good at all… :slightly_frowning_face:

“Have you tried rebooting?” taken to a whole new level.

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The report effect of iPhone 12 on implanted defibrillators or pacemakers is due to the array of magnets inside the phone (which are there for MagSafe).

Placing a magnet over a pacemaker will not cause “shutdown,” but it will put a pacemaker into what is called an asynchronous pacing mode, in which it paces without regard to what underlying heart rhythm may be present. This is not necessarily a problem, but there are potential risks if this occurs.

Pacing a magnet over an implanted defibrillator, as reported in the referenced article, can be dangerous as it will turn off the defibrillator’s ability to deliver a shock to the heart in the even of a ventricular arrhythmia, and with some models (not the ones reported in this paper) it can deactivate this function even after the magnet is no longer influencing the device.

Because of the concern regarding RF interference from cell phones on the function of pacemakers and defibrillators, patients are routinely warned about having their phones within 6 inches of their implanted device. My understanding is that Medtronic does not intend to issue any further guidance on this issue at this point, but I do not know of an official corporate response to the referenced paper.

I tried placing an iPhone 12 over a Medtronic defibrillator today using a device prior to implantation. It was not affected by the iPhone 12 placed in the exact same proximity to the device as a doughnut shaped magnet which did suspend device function. I don’t discount the findings in the referenced paper, but I did not reproduce them with an obviously limited ah hoc test.

(Note: if anyone out there has a pacemaker or defibrillator implanted or knows someone with such a device, please DO NOT try this on your own device or anyone else’s. It is not a good idea, and could be life threatening, to mess with your device’s function. If you have questions about your device and your phone or any other electronic device, please speak with your physician and do not experiment on yourself.)


Any magnet should never be placed over a pacemaker unless you are getting a specific EKG where a magnet is placed to see the intrinsic rhythm.

One of the things I loved about iPhone was the pointless but emotionally significant capability of playing a favorite movie over your heart. I guess this has to stop if you get a pacemaker.