Henry Ford cardiologists: iPhone 12 can disrupt defibrillator

Karen Bouffard
The Detroit News
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The life-saving function of an implantable defibrillator can be disrupted by the magnet in an iPhone 12, according to cardiologists at the Henry Ford Heart & Vascular Institute. 

Henry Ford Health System is calling the finding announced Thursday a "stunning" discovery that could potentially save the lives of more than 300,000 people who receive implantable defibrillators each year.  

The discovery was made by a team of cardiologists led by Dr. Gurjit Singh, a senior clinical cardiac electrophysiologist at Henry Ford Hospital in Detroit, and were published in the medical journal HeartRhythm on Jan. 4.

One of the new iPhone 12 equipped with technology for use with faster new 5G wireless networks that Apple unveiled Tuesday, Oct. 13, 2020.

Their discover got the attention of the federal Food and Drug Administration, which regulates medical devices, as well as the Association for the Advancement of Medical Instrumentation.

Apple, which produces the iPhone, published a warning Jan. 23 on its web page in response to the team's findings, the Detroit-based health system said in a press release. 

"Medical devices such as implanted pacemakers and defibrillators might contain sensors that respond to magnets and radios when in close contact," Apple's statement said in part.

"To avoid any potential interactions with these devices, keep your iPhone and MagSafe accessories a safe distance away from your device (more than 6 inches / 15 cm apart or more than 12 inches / 30 cm apart if wirelessly charging). But consult with your physician and your device manufacturer for specific guidelines."

Singh said the problem was first detected about a month ago by Dr. Joshua Greenberg, a cardiology fellow with Henry Ford who purchased an iPhone 12 Pro.

Greenberg read the details and learned that a magnet was inside the back of the device to help maximize charging — a new and unique feature that doesn't exist on other cell phones. 

Greenberg, who is studying heart rhythms at Henry Ford, immediately thought of the implications for patients who have implanted defibrillators, devices that have to be kept away from magnets or magnetic fields that can shut them off.  

"He came to me and said we need to find out if these magnets are strong enough that they can interfere with cardiac implantable devices," Singh recalled during a Thursday press briefing.  

A pacemaker provides electrical energy for the heart to beat and sets the heart rhythm at a healthy pace. A defibrillator shocks the heart if it stops beating to bring the patient back to life or can reset the heart to a healthy pace if it goes out of sync, Singh said. 

Defibrillators were designed years ago with a magnetic switch that shuts the device down if it comes into contact with an external magnet of enough strength, Singh said. The switch was included as a safety measure, so that if a defibrillator malfunctions and continues to shock the patient it can be quickly shut down, he noted.

"When I was first reading about the iPhone, they said the magnet was so strong you could actually attach it to your refrigerator," Greenberg said. 

The team decided to find out what would happen if the phone came close to a real patient's defibrillator, Singe said.

"We brought the iPhone pretty much very close to the chest, (above) the patient's defibrillator over the skin and the dressing, and we immediately discovered that the magnet de-activated the defibrillator," Singe recalled. 

"We produced these results multiple times and every time the iPhone was brought in close to the defibrillator, the defibrillator was deactivated."

The cardiologists now are awaiting approval of a study that will look at the effects of the phone on pacemakers as well as defibrillators, Singh said.

Pacemakers have a similar magnetic switch. But instead of shutting down around a strong enough magnet, they are reprogrammed to make the heart beat at a pre-fixed pace regardless of any atrial or ventricular activity.  


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