SILVER SPRING, Md. — Electronic devices such as smartphones and watches can interfere with pacemakers and defibrillators, warns a new study. Magnets in new-generation electronics could block medical devices unless they are more than six inches away, according to the U.S. Food and Drug Administration.

Pacemakers and cardiac defibrillators keep a patient’s heart beating regularly and not too slowly by sending electrical pulses.

Doctors implant around 200,000 pacemakers into patients every year in the U.S., making it one of the most common types of heart operations. Surgeons can pause these devices during surgery or medical treatment where interference is possible, also known as “magnet mode.”

However, magnetic fields greater than 10G (magnetic flux density) may accidentally activate them and cause serious harm to the patient. Historically, only large magnets in some stereo speakers and electric motors are big enough to trigger magnet mode.

New technology may endanger heart patients

Now, with rare earth metals becoming a part of a range of electronics, earphones, door locks, and mobile phones may also produce strong magnetic fields.

“Ensuring the safety of our nation’s medical devices is a cornerstone of our consumer protection mission, especially as technology continues to advance,” says study author Seth Seidman in a media release.

“As part of this work, the agency reviewed recently published articles describing the possibility that certain newer cell phones, smart watches and other consumer electronics with high field strength magnets may temporarily affect the normal operation of implanted electronic medical devices, such as pacemakers and implantable defibrillators,” Seidman continues. “Based on our review, we decided to conduct our own testing to confirm and help inform appropriate recommendations for patients and consumers.”

Researchers tested the magnetic field of all iPhone 12 and Apple Watch 6 models at varying distances from the medical equipment. All of the devices had static magnetic fields significantly greater than 10G in close proximity.

However, when the team maintained a separation distance of six inches or more, they did not trigger the heart devices’ magnet mode.

How can you protect your heart from electronics?

Due to these results, Seidman says the FDA is taking steps to provide information for patients and healthcare providers to ensure they are aware of potential risks. Doctors and patients can take simple proactive and preventive measures like keeping certain cell phones and smart watches six inches away from implanted medical devices. Study authors also advise patients not to carry consumer electronics in a pocket over the medical device.

While the risk to patients remains low, the magnetic interference produced by electronic devices will likely continue to rise. Patients equipped with a pacemaker or defibrillator should therefore take the necessary precautions.

“We believe the risk to patients is low and the agency is not aware of any adverse events associated with this issue at this time. However, the number of consumer electronics with strong magnets is expected to increase over time,” Seidman adds.

“Therefore, we recommend people with implanted medical devices talk with their health care provider to ensure they understand this potential risk and the proper techniques for safe use. The FDA will continue to monitor the effects of consumer electronics on the safe operation of implanted medical devices.”

The findings appear in the journal Heart Rhythm.

South West News Service writer Tom Campbell contributed to this report.

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