Cardiologists: iPhone 12 can deactivate defibrillators, pacemakers By: WXYZ Staff and last updated 2021-02-05 08:11:38-05 Cardiologists at Henry Ford Health System in Detroit say they discovered that the iPhone 12 has the ability to deactivate implantable cardiac devices when held too close to a personâs chest. Appleâs iPhone 12 series features a strong magnet to help maximize charging, which can cause issues with cardiac devices, according to a press release from Henry Ford. The health system says the phone's magnet can turn off heart defibrillators and can cause a ...