Report: iPhone MagSafe Technology Interferes with Some Pacemakers, Defribrillators

A new report is sounding the alarm on the potential for magnetic interference with newer Apple iPhones and cardiac implantable electronic devices (CIED), including pacemakers and implantable cardioverter defibrillators.

Despite being a small study, including just 3 patients and ex vivo testing of 11 devices, results demonstrate clinically identifiable magnetic interference among 11 of 14 devices when within 1.5 cm of the iPhone 12 Pro Max, underlining the potential for magnetic interference in devices using MagSafe technology.

“We have always known that magnets can interfere with cardiac implantable electronic devices, however, we were surprised by the strength of the magnets used in the iPhone 12 magnet technology,” said lead study investigator Michael Wu, MD, Assistant Professor of Medicine and Director of the Clinical Cardiac Electrophysiology Fellowship Program in the cardiology division at the Rhode Island and Miriam Hospital’s Lifespan Cardiovascular Institute and Brown University’s Warren Alpert School of Medicine, in a statement from the American Heart Association. “In general, a magnet can change a pacemaker’s timing or deactivate a defibrillator’s lifesaving functions, and this research indicate the urgency for everyone to be aware that electronic devices with magnets can interfere with cardiac implantable electronic devices.”

With Apple’s proprietary MagSafe technology capable of generating magnet field strength greater than 50 gauss (G), investigators sought to determine whether this technology could cause clinically significant magnet interference with CIEDs, which was recently addressed in an update by the US Food and Drug Administration. To determine these devices would interfere with these devices, investigators designed their study to have an in vivo and an ex vivo component.

The in vivo portion of the study included 3 consecutive patients presenting for a generator change or device interrogation. Devices represented within this population included the Medtronic Amplia MRI Quad CRT‐D, Abbott Medical 1231‐40 Fortify VR, and Boston Scientific V273 Intua CRT‐P. Investigators noted a standard donut magnet was used to ensure magnet reversion could be triggered in all 3 patients.

The iPhone 12 Pro Max triggered magnet reversion mode in all 3 devices. Investigators pointed out introduction of the iPhone 12 Pro Max resulted in the inhibition of tachytherapies in the Medtronic and Abbott defibrillators, but the Boston Scientific device appeared to be less susceptible as they were only able to elicit transient temporary asynchronous pacing but no sustained response.

Of the 11 devices included in the ex vivo portion of the study, 5 were implantable cardioverter defibrillators and 6 were pacemakers. This group included 4 Medtronic devices: the Visia AF MRI ICD, the Azure, the Advisa MRI, and the Adapta. Boston Scientific devices included the Dynagen ICD, Emblem MRI S-ICD, Accolade MRI, and U125 Valitude. Abbott devices included the Fortify Assura DR ICD, Ellipse DR ICD, and the Assurity MRI.

Similar to the in vivo portion, a standard donut ring was used to ensure magnet mode activation was possible for each packaged device. For the purpose of analysis, the iPhone 12 Pro Max was placed directory over the packaged CIED and the magnet strength of the iPhone 12 Pro Max was measured using a magnetometer.

Results indicated the selected Medtronic and Abbott devices tested were susceptible to electromagnetic interference, but the Boston Scientific devices appeared to be less susceptible, with no observable effect among all but the U125 Valitude, which experienced temporary asynchronous pacing. Exposure resulted in the inhibition of tachytherapies in the Medtronic and Abbott defibrillators tested, while asynchronous pacing occurred among the Medtronic and Abbott pacemakers exposed to the iPhone 12 Pro Max.

“The American Heart Association and manufacturers of pacemakers and implantable cardioverter defibrillators have long recommended that cell phones be used in the ear opposite the side of the body of an implanted device, and that the cell phones be kept at least 10 cm away from the device, therefore not in a shirt or coat pocket on the same side as the cardiac device,” said N.A. Mark A. Estes, MD, Director of the Clinical Cardiac Electrophysiology Fellowship Program at the Heart and Vascular Institute of the University of Pittsburgh School of Medicine and an American Heart Association volunteer, in the aforementioned statement. “While the risk from temporary interference was only tested with specific devices and cell phones, the Association reminds people with cardiac implantable electronic devices to remain informed of the latest FDA guidance for their heart device, the manufacturers’ safety guidelines and to contact their health care professional with any questions or concerns.“

This study, “Magnetic Interference on Cardiac Implantable Electronic Devices From Apple iPhone MagSafe Technology,” was published in the Journal of the American Heart Association.