Pacemakers can be hacked but that’s not news. We’ve known that for a while.
Newer models are even easier to hack than were the older models. Progress being what it is. Most pacemakers are interrogated and adjusted in the doctor’s office or the Pacemaker Clinic by placing a “wand” over the pacemaker and then using an attached computer to retrieve data stored inside and/or change the parameters of the pacemaker—-changing sensing, pacing thresholds and rates, that sort of thing. Many newer models allow for more remote access—-from several feet away. Think “blue tooth” for a pacemaker.
This more “remote” access allows for hacking to take place without direct contact with the patient. The pacemaker can be changed, even turned off, which in someone who is “pacemaker dependent” for their heartbeats can be catastrophic, even deadly. Fortunately most pacemaker recipients are NOT pacer dependent so even if the device is turned off they would still do fine. Maybe a bit weak, tired, and dizzy, but not dead from heart stoppage.
Now it seems that, though this can still be done, traces are left behind. Makes getting away with such tampering more difficult.
Guess you crime writers will have to find another way to off your characters who have pacemakers.