A device programmer showing the suspension of ICD therapies (orange bar, red arrow) with iPhone 12 laying over patient’s chest (green arrow) and fluoroscopy of iPhone 12 showing the circular magnet array (yellow arrow). Image from a small study at Henry Ford Hospital. Read the full study
May 14, 2021 — The U.S. Food and Drug Administration (FDA) is advising patients and caregivers to keep any consumer electronic devices, such as cell phones and smart watches, at least 6 inches away from implanted electrophysiology (EP) medical devices, such as pacemakers and implantable cardioverter defibrillators (ICD).
The FDA is aware that some newer consumer electronic devices, including cell phones and smart watches, have magnets that may cause some implanted medical devices to go into a magnetic safe mode and temporarily suspend normal operation. The magnetic safe mode allows for safe operation during certain medical procedures such as undergoing an MRI imaging scan.
The FDA believes the risk to patients is low, and the agency is not aware of any adverse events associated with this issue at this time. The FDA continues to monitor all relevant scientific information (including adverse event reports) about this ongoing issue and will continue to inform the public and healthcare providers, if the need arises based on risk analysis.
Some consumer electronic devices, such as certain cell phones and smart watches, use high-field strength magnets. Recent studies have shown that consumer electronic devices with high-field strength magnets may cause certain implanted medical devices to switch to “magnet mode” and suspend normal operations until the magnet is moved away from the medical device.
These safety features are typically engaged by physicians with the use of a high field strength magnet that is placed near the implanted device placing it into a “magnet mode” for MRI scans. Removal of the magnetic field causes the device to return to normal operation.
Precautions for Patients With Pacemakers, ICDs and CRT Devices to Prevent Interference from Cell Phones and Smart Watches
The FDA recommends patients keep any consumer electronic devices that may create magnetic interference, including cell phones and smart watches, at least 6 inches away from implanted medical devices, in particular cardiac defibrillators. Many implanted medical devices have FDA-approved information written for patients (patient labeling), which cautions patients to keep all cell phones and smart watches at least six inches from the implanted medical device.
People with implanted medical devices may want to take some simple precautions, including:
• Keep the consumer electronics, such as certain cell phones and smart watches, six inches away from implanted medical devices.
• Do not carry consumer electronics in a pocket over the medical device, such as a chest pocket in a coat or shirt.
• Check your device using your home monitoring system, if you have one.
• Talk to your health careprovider if you are experiencing any symptoms or have questions regarding magnets in consumer electronics and implanted medical devices.
When near high strength magnets, devices with a magnetic safe mode could stop working or change how the device works. For example, an implantable cardioverter cardiac defibrillator (ICD) may be unable to detect tachycardia events. Or it may change the operational mode of the devices such as turning on asynchronous mode in a pacemaker.
Cardiac implanted electronic devices are intended to support heart rhythm disorders, such as slow or fast heart rates. When the device stops working, a patient may experience dizziness, loss of consciousness or even death if therapy is not delivered when lifesaving shocks are required.
The FDA emphasized it is important to avoid interference between cell phones and smart watches and a patient's heart device by keeping them at least 6 inches (15 centimeters) away from implanted medical devices. Also, do not place cell phones, smart watches, and other consumer electronics close to your implanted medical device.
The FDA is aware of published articles which describe the effect that sufficiently strong magnetic fields can turn on the magnetic safe mode when in close contact. The FDA also conducted its own testing on some products that use the high field strength magnet feature and have confirmed the magnetic field is both consistent with the publications and strong enough to turn on the magnetic safety mode of the medical devices in question. The FDA believes the risk to patients is low, and the agency is not aware of any adverse events associated with this issue at this time.
The FDA continues to monitor all relevant scientific information about this ongoing issue and will continue to take appropriate action, including informing the public and providing additional information, if the need arises based on its risk analysis.
Related article from January 2021: iPhone 12 May Cause Implantable Cardioverter Defibrillators to Malfunction.
The FDA includes a list of recent articles from peer review journals that raise concerns over the cell phone magnet issue:
- Letter to the Editor: Lifesaving Therapy Inhibition by Phones Containing Magnets
- Letter to the Editor: Phone Interaction with CIEDs: Problem or Not External Link Disclaimer
- To the Editor: New phones, old problem? Interference with cardiovascular implantable electronic devices by phones containing magnets External Link Disclaimer
- Study: iPhone 12 Magnets Can Deactivate Cardiac Devices External Link Disclaimer
- Henry Ford Cardiologists Find Apple iPhone 12 Magnet Deactivates Implantable Cardiac Devices External Link Disclaimer
- About the magnets inside iPhone 12, iPhone 12 mini, iPhone 12 Pro, iPhone 12 Pro Max, and MagSafe accessories - Apple Support
May 22, 2023 
