Apple Watch ECG Helps Detect Case of Coronary Ischemia Missed by Hospital ECG

The single-lead ECG function on Apple Watch isn't meant to be as informative or as sensitive as the multi-lead ECGs you might get in a doctor's office or hospital, which use several points of contact. However, a new article in The European Heart Journal tells the story of an 80-year-old woman whose Apple Watch detected evidence of a heart condition that was missed by a hospital ECG (via 9to5Mac).

applewatchseries4ecgfeature
According to the article, the woman presented at University Medical Center Mainz, Germany, complaining of chest pain, irregular heart rhythm, and lightheadedness. When doctors at the hospital performed a 12-channel ECG, it revealed "no evidence for ischemia," which occurs when blood flow to the heart is reduced, preventing the heart muscle from receiving enough oxygen.

However the woman then showed doctors her Apple Watch ECG results, which included "tracings with marked ST-segment depression." After studying the Apple Watch results, doctors did indeed see evidence of myocardial ischemia, and the woman was transferred to the catheterization lab for a "left main stem stenosis and a left anterior descending/diagonal bifurcation lesion," and treatment with coronary artery stenting.

Essentially, the Apple Watch ECG recordings showed evidence of a heart condition that the hospital's specialized equipment failed to pick up, and that convinced the doctors to treat the patient, who left the hospital the next day.

The report concludes that the Apple watch may be used to reliably detect myocardial ischaemia.

The development of smart technologies paves the way for new diagnostic possibilities. In the case of the Apple Watch, after the mobile application is installed, the records an ECG when a finger is placed on the watch’s digital crown. A 30-s tracing is stored in a PDF file that can be retrieved from the application.

Thus, the Apple Watch may be used not only to detect atrial fibrillation or atrioventricular-conduction disturbances but also to detect myocardial ischemia. An apple a day may keep myocardial infarction away.

You can read the full report here. Rumors regarding the Apple Watch Series 6, expected to launch later this year, suggest additional health-related features mental, including blood oxygen detection, sleep tracking, and stress detection.

Related Roundup: Apple Watch Series 6
Buyer's Guide: Apple Watch (Buy Now)

Top Rated Comments

chucker23n1 Avatar
7 months ago


No way an Apple Watch flagged up an abnormality a properly maintained 12-lead ECG failed to spot.

A smartwatch sensor has far fewer leads, yes, but it also collects a far more comprehensive set of data.


More likely, whoever performed that ECG, attached the leads etc. is at fault here, not the equipment itself.

Er, yes. So what? "Your data doesn't matter because I should've picked up the data myself instead"? Like, maybe fire the doctor responsible for negligence, but even so, the fact of the matter remains that in practice, the smartwatch collected data that the doctors' professional equipment did not. IOW, the smartwatch helped. Should it have been necessary at all? The correct answer is: it doesn't matter, because it was there.


The Apple Watch is the only product line whose execution and focus is giving me some hope right now. I'm curious what they'll come up with for series 6 after the 5 being more or less 4s.

My biggest hope is the Series 6 will drive down the price of older models. Maybe the 4 or 5 will become the new $199 model. Then I'll upgrade to that from my Series 0.
Score: 13 Votes (Like | Disagree)
NightFox Avatar
7 months ago
Rather than the Apple Watch being in some way superior to specialized equipment as the article seems to imply, wasn't it just the case that the symptoms here were only occasional, so needed an extended monitoring period to present themselves? Of course the Apple Watch is a real life-saver for situations such as this where short-duration ECG tests might not otherwise pick up latent problems, but directly comparing the two seems a bit apples and pears.
Score: 11 Votes (Like | Disagree)
[AUT] Thomas Avatar
7 months ago
IMHO, and that is certainly point for discussion, medical data needs to be put (anonymized) to work using big data based deep learning. The benefits IMHO greatly outweigh the risks. And that comes from someone using Apple devices mostly because of privacy and security.

No cardiologist can have looked at and analyzed as many ECGs in his entire life than a computer can in a couple minutes.

That will NOT put cardiologists out business nor make looking at ECG prints obsolete BUT it will greatly help in not missing something and aid in (not replace!) human diagnosis.

And that goes for many other conditions as well.

[Edit: "replace" was "supplement" previously. Meaning should remaint the same, that the doctor is still doing the diagnosis, with the results from AI as hint or inspiration in finding the cause of the problem.]


No way an Apple Watch flagged up an abnormality a properly maintained 12-lead ECG failed to spot.

More likely, whoever performed that ECG, attached the leads etc. is at fault here, not the equipment itself.

Her clinical history alone would have given cause for caution and a repeat ECG (correctly administered) would have rendered this “publication” irrelevant.

Absolutely true, but it doesn't change the fact, that a small handheld device picked up something that would have been otherwise missed.
Score: 11 Votes (Like | Disagree)
djcerla Avatar
7 months ago


No way an Apple Watch flagged up an abnormality a properly maintained 12-lead ECG failed to spot.

“No way” but this happened anyway. Reality not always conforms to current dogma.
Score: 10 Votes (Like | Disagree)
Saturnine Avatar
7 months ago
There is no downside to this story. Whether it's marketing hype or not, the fact remains that the Apple Watch picked up something that was not picked up by proper medical equipment. Whether or not it should have been is a different matter entirely. Having a single, unobtrusive device to wear which can detect and inform potentially serious medical issues can only be a positive.

I've suffered with, sometimes quite severe, sleep issues for a long time now. My experience with the medical services hasn't been great. It's not their fault - it's just difficult to get a referral to specialists and then actually have the symptoms present while under monitoring. If the next Apple Watch dues have certain, specific, sleep tracking features then it is potentially a really useful device for me. I just don't understand the cynicism that surrounds good-news stories.
Score: 10 Votes (Like | Disagree)
Veinticinco Avatar
7 months ago
No way an Apple Watch flagged up an abnormality a properly maintained 12-lead ECG failed to spot.

More likely, whoever performed that ECG, attached the leads etc. is at fault here, not the equipment itself.

Her clinical history alone would have given cause for caution and a repeat ECG (correctly administered) would have rendered this “publication” irrelevant.
Score: 9 Votes (Like | Disagree)

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