Apple announced its iPhone 12 in late 2020 as “the best iPhone ever” with “a powerful 5G experience and advanced technologies that push the boundaries of innovation for users who want the most out of iPhone.”

One innovation that users may not have anticipated was the ability of this iPhone iteration to deactivate their implantable cardiac defibrillators (ICD), writes Dr Anthony Pearson, a noninvasive cardiologist and professor of medicine at St Louis University School of Medicine.

ICDs and cardiac pacemakers are designed to respond to nearby magnets by changing their function. In essence, these sophisticated devices are rendered dumb. Amongst the advanced technologies Apple put in the iPhone 12 was “an array of magnets around the wireless charging coil” for pairing with various MagSafe fitted chargers and accessories:

Henry Ford Hospital electrophysiologist Dr Joshua Greenberg became concerned about possible adverse interactions between iPhone’s magnets and implantable cardiac devices and performed a test on a patient with an ICD manufactured by Medtronic.

“Once the iPhone was brought close to the ICD over the left chest area, immediate suspension of ICD therapies was noted and persisted for the duration of the test.”

This is a big deal because “suspension of life-saving therapies” means that, should the patient go into ventricular tachycardia or fibrillation during this time, they would just drop dead without receiving a life-saving shock from the ICD.