Medical Doctors Underline Potential Risk of iPhone 12 Interference With Pacemakers

Apple's warning to keep the iPhone 12 away from cardiac devices due to electromagnetic interference was further underlined by U.S. cardiologists this week in a new report (via NBC25 News).

iphone12magsafe
Apple's ‌iPhone‌ 12 series includes an array of magnets that help align the phone on Apple's MagSafe charging accessory to maximize charging, and Apple already advises users with implanted pacemakers and defibrillators to keep ‌iPhone‌ and ‌MagSafe‌‌ accessories a safe distance away from such devices.

To test the extent of the risk, Henry Ford Heart and Vascular Institute cardiologist Gurjit Singh and his colleagues recently carried out further testing to see just how much of an influence the Apple products have.

According to Dr. Singh, more than 300,000 people in the U.S. undergo surgery to implant one of these devices each year, and around one in four smartphones sold last year was an ‌iPhone‌ 12. The cardiac devices have switches that respond to an external magnet to change how the device functions, which allows them to be controlled without the requirement of surgery.

Curious about potential interference with electrical devices, Dr. Singh and his colleagues took an ‌iPhone‌ 12 Pro and passed it over the chest of a patient with an implantable defibrillator.

"When we brought the iPhone close to the patient's chest the defibrillator was deactivated," said Dr. Singh. "We saw on the external defibrillator programmer that the functions of the device were suspended and remained suspended. When we took the phone away from the patient's chest, the defibrillator immediately returned to its normal function."

"We were all stunned," he said. "We had assumed that the magnet would be too weak in a phone to trip the defibrillator’s magnetic switch."

The findings are significant, since Dr. Singh is an expert in the use of devices such as implantable defibrillators that detect an irregular heartbeat and shock the heart back into a normal rhythm, and pacemakers that use electricity to keep the heart beating. Following the discovery, Dr. Singh and his colleagues immediately submitted a report of their findings to the HeartRhythm medical journal that was published on January 4, 2021.

"We believe our findings have profound implications on a large scale for the people who live daily with these devices, who without thinking, will place their phone in their shirt pocket or upper pocket or their coat – not knowing that it can cause their defibrillator or pacemaker to function in a way that could potentially be lethal."


The comments underline medical evidence published in January which cautioned that ‌‌iPhone‌ 12‌ models and related ‌MagSafe‌ devices can "potentially inhibit lifesaving therapy in a patient" due to magnetic interference with implanted medical devices. Apple provides more information about this issue in the "Important safety information for iPhone" section of the ‌‌iPhone‌‌ User Guide.

Related Forum: iPhone

Popular Stories

iphone 16 display

iPhone 17's Scratch Resistant Anti-Reflective Display Coating Canceled

Monday April 28, 2025 12:48 pm PDT by
Apple may have canceled the super scratch resistant anti-reflective display coating that it planned to use for the iPhone 17 Pro models, according to a source with reliable information that spoke to MacRumors. Last spring, Weibo leaker Instant Digital suggested Apple was working on a new anti-reflective display layer that was more scratch resistant than the Ceramic Shield. We haven't heard...
iPhone 17 Air Pastel Feature

iPhone 17 Reaches Key Milestone Ahead of Mass Production

Monday April 28, 2025 8:44 am PDT by
Apple has completed Engineering Validation Testing (EVT) for at least one iPhone 17 model, according to a paywalled preview of an upcoming DigiTimes report. iPhone 17 Air mockup based on rumored design The EVT stage involves Apple testing iPhone 17 prototypes to ensure the hardware works as expected. There are still DVT (Design Validation Test) and PVT (Production Validation Test) stages to...
Beyond iPhone 13 Better Blue

20th Anniversary iPhone Likely to Be Made in China Due to 'Extraordinarily Complex' Design

Monday April 28, 2025 4:29 am PDT by
Apple will likely manufacture its 20th anniversary iPhone models in China, despite broader efforts to shift production to India, according to Bloomberg's Mark Gurman. In 2027, Apple is planning a "major shake-up" for the iPhone lineup to mark two decades since the original model launched. Gurman's previous reporting indicates the company will introduce a foldable iPhone alongside a "bold"...
iphone 17 air iphone 16 pro

iPhone 17 Air USB-C Port May Have This Unusual Design Quirk

Wednesday April 30, 2025 3:59 am PDT by
Apple is preparing to launch a dramatically thinner iPhone this September, and if recent leaks are anything to go by, the so-called iPhone 17 Air could boast one of the most radical design shifts in recent years. iPhone 17 Air dummy model alongside iPhone 16 Pro (credit: AppleTrack) At just 5.5mm thick (excluding a slightly raised camera bump), the 6.6-inch iPhone 17 Air is expected to become ...
apple watch ultra yellow

What's Next for the Apple Watch Ultra 3 and Apple Watch SE 3

Friday April 25, 2025 2:44 pm PDT by
This week marks the 10th anniversary of the Apple Watch, which launched on April 24, 2015. Yesterday, we recapped features rumored for the Apple Watch Series 11, but since 2015, the Apple Watch has also branched out into the Apple Watch Ultra and the Apple Watch SE, so we thought we'd take a look at what's next for those product lines, too. 2025 Apple Watch Ultra 3 Apple didn't update the...
iPhone 17 Pro Blue Feature Tighter Crop

iPhone 17 Pro Launching Later This Year With These 13 New Features

Wednesday April 23, 2025 8:31 am PDT by
While the iPhone 17 Pro and iPhone 17 Pro Max are not expected to launch until September, there are already plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models as of April 2025: Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone ...
AirPods Pro 3 Mock Feature

AirPods Pro 3 Just Months Away – Here's What We Know

Tuesday April 29, 2025 1:30 am PDT by
Despite being more than two years old, Apple's AirPods Pro 2 still dominate the premium wireless‑earbud space, thanks to a potent mix of top‑tier audio, class‑leading noise cancellation, and Apple's habit of delivering major new features through software updates. With AirPods Pro 3 widely expected to arrive in 2025, prospective buyers now face a familiar dilemma: snap up the proven...
iPhone 17 Pro on Desk Feature

All iPhone 17 Models Again Rumored to Feature 12GB of RAM

Tuesday April 29, 2025 3:36 am PDT by
All upcoming iPhone 17 models will come equipped with 12GB of RAM to support Apple Intelligence, according to the Weibo-based leaker Digital Chat Station. The claim from the Chinese leaker, who has sources within Apple's supply chain, comes a few days after industry analyst Ming-Chi Kuo said that the iPhone 17 Air, iPhone 17 Pro, and iPhone 17 Pro Max will all be equipped with 12GB of RAM. ...

Top Rated Comments

adamlbiscuit Avatar
55 months ago
My mum had a pacemaker fitted in 2019. Around that time she owned an original iPhone SE (2016), and even then she was told to keep it well away from her chest. This advice isn't new to the iPhone 12 at all, or at least in my mums case it wasn't.

She took the advice to heart (no pun intended) and since always kept her phone in a bag rather than a pocket, and even used the phone on loud speaker during phone calls (which you could argue is overkill but she likes to play it safe & who could blame her).

She now has an iPhone 12 mini & hasn't changed her handling of the device when compared to the SE. Point is, if you have a pacemaker fitted you're usually advised to keep any mobile device a safe distance from it and this was the case well before the iPhone 12.

That said, as someone whose mother has a pacemaker fitted I'm always grateful to see this issue highlighted. I just think it's worth pointing this out as a lot of people may mistakenly think this is unique to iPhone 12 models & it isn't. It's simply the case that the magnets are an additional thing to bear in mind, in a long list of reasons why you should keep any phone a safe distance from such devices.
Score: 25 Votes (Like | Disagree)
henryhbk Avatar
55 months ago
So it is important to differentiate between danger to a patient that is pacer dependent versus a patient who has a pacemaker as backup for an intermittent condition (note: I am a doctor). For instance if you are constantly pacer dependent (i.e. for whatever reason your sinus node isn't doing a proper job establishing your heart rate/rhythm) then this could be deadly (depending on what your non-paced escape rhythm is). Versus for instance if once in a blue moon your heart rate becomes dangerously slow and you faint, then it's not going to cause a problem (given the probability of you needing the pacer backup at the exact moment you place your iPhone 12 on your chest).

Modern pacemakers (or electronics in general) are remarkably resistant to EMI (particularly since most pacemakers now are internet connected, they certainly can handle cellular/wifi signals nearby since they themselves generate wifi or BT). The magnet is a specific off-switch (that's a feature, like when I want to take an EKG of a patient with a pacemaker and want to see the underlying heart itself, I put a ring shaped magnet (we leave them stuck on the side of the EKG cart) so the pacemaker shuts off, so we can see, then after the procedure I remove the magnet. i make the same calculation of risk when I place the order for the EKG as to whether you can safely deactivate the pacer for a little while to do the EKG (some patients yes, some no)
Score: 25 Votes (Like | Disagree)
Piggie Avatar
55 months ago
I could see a potential bedtime scenario that you'd need to be sure never happened.
And I'm 100% sure the following scenario has happened to hundreds if not thousands of people many times.

Laying in bed, tired, messing with your phone, and you drift off to sleep, your hands flop down and your phone lands on your chest.

Have to be sure you never ever put yourself in such a situation with one of these phones.
Must be 1000's of people every single night in bed, laying down doing this exact thing.
Score: 22 Votes (Like | Disagree)
verpeiler Avatar
55 months ago
If you have a pacemaker, don't put your iPhone near your heart. Got it.
I guess smartphones in general shouldn't be near a pacemaker anyway.
Score: 18 Votes (Like | Disagree)
Whathappened Avatar
55 months ago
please Apple get rid of that magnet. It is not important how fast we charge wirelessly as long as you provide one day battery life. Most of us charge overnight. My car has a (slow) charging mat, my office has one, the phone is being charged all the time.
Score: 10 Votes (Like | Disagree)
Apple_Robert Avatar
55 months ago

So it is important to differentiate between danger to a patient that is pacer dependent versus a patient who has a pacemaker as backup for an intermittent condition (note: I am a doctor). For instance if you are constantly pacer dependent (i.e. for whatever reason your sinus node isn't doing a proper job establishing your heart rate/rhythm) then this could be deadly (depending on what your non-paced escape rhythm is). Versus for instance if once in a blue moon your heart rate becomes dangerously slow and you faint, then it's not going to cause a problem (given the probability of you needing the pacer backup at the exact moment you place your iPhone 12 on your chest).

Modern pacemakers (or electronics in general) are remarkably resistant to EMI (particularly since most pacemakers now are internet connected, they certainly can handle cellular/wifi signals nearby since they themselves generate wifi or BT). The magnet is a specific off-switch (that's a feature, like when I want to take an EKG of a patient with a pacemaker and want to see the underlying heart itself, I put a ring shaped magnet (we leave them stuck on the side of the EKG cart) so the pacemaker shuts off, so we can see, then after the procedure I remove the magnet. i make the same calculation of risk when I place the order for the EKG as to whether you can safely deactivate the pacer for a little while to do the EKG (some patients yes, some no)
This is the kind of information people on the forum needed to be educated about. Thank you, Doctor.
Score: 9 Votes (Like | Disagree)