A new study published by the Heart Rhythm Society indicates that the iPhone 12 can interfere with a pacemaker if the phone is placed close to a patient’s heart. But the study, which was designed to look at whether the magnetic array that enables the iPhone 12’s new MagSafe charging technology had an effect on implantable cardioverter defibrillators (or ICDs), raises more questions than it answers.
Apple’s newest iPhones have a circular array of magnets built into their backs, which allows them to snap to a MagSafe charging puck or compatible accessory (such as a phone case). But pacemakers have a switch that can be deactivated with an external magnetic field, and when researchers from the Henry Ford Heart and Vascular Institute placed an iPhone 12 above the heart of a patient with an implanted Medtronic pacemaker, the pacemaker’s operations were suspended every time.
“Once the iPhone was brought close to the ICD over the left chest area, immediate suspension of ICD therapies was noted which persisted for the duration of the test,” the study’s authors write. “This was reproduced multiple times with different positions of the phone over the pocket.”
As 9to5Mac notes, Apple acknowledges this is a risk: “iPhone contains magnets as well as components and radios that emit electromagnetic fields. These magnets and electromagnetic fields may interfere with medical devices, such as pacemakers and defibrillators. Though all iPhone 12 models contain more magnets than prior iPhone models, they’re not expected to pose a greater risk of magnetic interference to medical devices than prior iPhone models.”
So the question remains as to whether the iPhone 12 is more likely to interfere with a pacemaker than other devices. The researchers pointed to studies that indicate smartphones without the kind of magnetic arrays found in the latest iPhone have a low risk of interfering with ICDs, but also noted that devices like fitness trackers have also been found to deactivate a pacemaker. More research is needed, preferably testing a wider range of phones and more ICDs, to determine if the iPhone 12 is riskier to use for patients with pacemakers than other phones are.
Due to the way pacemakers are designed, they can be easily activated (or deactivated) by ambient sources with magnetic fields, including a Fitbit or a vape pen, according to medical news service Medical Xpress. This doesn’t have to be the case, but changing it will require medical device manufacturers to redesign their pacemakers.
Until more research is done, if you have a pacemaker and also own an iPhone 12 — or any device that includes magnets — consult your doctor to see what distance they recommend you keep the device away from your heart. At the very least, you might not want to wear your phone in a pocket directly over your chest.