EKG - ventricular arrythmias not recognized

[Dave00]

So, as a primary care internist, I had my first experience of an Apple Watch potentially saving a patient's life. She'd had palpitations before, a normal EKG and Holter monitor, though she was not having symptoms during either of those tests. She decided to check an Apple Watch ECG while having symptoms, and brought that to her appointment. I was stunned to look at the tracing, which showed a period of prolonged ventricular tachcardia deteriorating into a brief period of ventricular fibrillation before going back into sinus rhythm.

While the ability to get the tracing likely saved her life, it's worrisome that the Apple Watch did not flag either the ventricular arrythmia or the fact that her heart rate was over 200 during the episode. It looks like the heart rate sensor is designed only to notice irregularity or a heart rate under 40, and the ECG is really only looking for atrial fibrillation. I can't figure out why this would be, given that an EKG or telemetry machine with markedly less sophisticated hardware can do so fairly reliably. The tracings are also sufficiently detailed to show things like long QT syndrome, but this also is not something flagged by the watch.

I am wondering if anyone has any insight into why Apple has not expanded analysis to evaluate beyond atrial fibrillation or bradycardia (low heart rate). There is incredible untapped potential here, if they would choose to use it.

Dave

 

[DontGetTheCheese]

So, as a primary care internist, I had my first experience of an Apple Watch potentially saving a patient's life. She'd had palpitations before, a normal EKG and Holter monitor, though she was not having symptoms during either of those tests. She decided to check an Apple Watch ECG while having symptoms, and brought that to her appointment. I was stunned to look at the tracing, which showed a period of prolonged ventricular tachcardia deteriorating into a brief period of ventricular fibrillation before going back into sinus rhythm.

While the ability to get the tracing likely saved her life, it's worrisome that the Apple Watch did not flag either the ventricular arrythmia or the fact that her heart rate was over 200 during the episode. It looks like the heart rate sensor is designed only to notice irregularity or a heart rate under 40, and the ECG is really only looking for atrial fibrillation. I can't figure out why this would be, given that an EKG or telemetry machine with markedly less sophisticated hardware can do so fairly reliably. The tracings are also sufficiently detailed to show things like long QT syndrome, but this also is not something flagged by the watch.

I am wondering if anyone has any insight into why Apple has not expanded analysis to evaluate beyond atrial fibrillation or bradycardia (low heart rate). There is incredible untapped potential here, if they would choose to use it.

Dave

This may help.

Heart health notifications on your Apple Watch - Apple Support

Get notifications for high or low heart rates and irregular rhythms.

support.apple.com

At least the heart rate can be detected. Not sure about the rest.

 

[BigMcGuire]

I have heart arrhythmias and Apple Watch has never given me a warning or notice about them. I gave an ECG reading to a nurse and she identified it right away using a term I can't remember at the moment. But I've always had them for most of my life (my father does too) so I was not alarmed, just curious about the Apple Watch - and it's never said a thing about them.

My wife will get high heart rate notifications now and then (120+bpm while stationary) due to her stressful work and I usually get notified about them a day after strangely enough (we share health data via Apple Family).

My guess the liability is an issue? I'm hoping in my lifetime that our wearables will start taking a more active role in our health monitoring.

I too would love to see this explored more. The accuracy of the Ultra vs my S7 is noticeably better.

 

[chanerz]

The problem is it is only programmed to detect afib. That is all. Doesn’t care all other rhythms. Even if you’re already asystole, doesn’t matter.

 

[DontGetTheCheese]

Forgot to add something, but I’ve had ectopic beats (PVC’S) and Omron BPM‘s detect them. I’ve run an ECG on the watch and you can‘t miss them (see link below). The OP has a point. PVC’s, at least mine are stress-based, so not a big deal but Apple needs to offer more than a bunch of BS about all the lives they’re supposedly saving with the watch.

i’m so cynical about Apple at this point that it wouldn’t surprise me if they can already do this but are just saving it for a watch iteration to sell more watches.

https://forums.macrumors.com/threads/heart-hiccups.2170767/

 

[BenGoren]

Since the FDA considers the watch a medical device in this context, Apple needs approval for this sort of thing. And just because it’s easy for you as a trained physician to spot the problem doesn’t mean that there’s a reliable way for the watch to do so. Or, if there is such a way, it’s not necessarily good enough to pass FDA muster.

Do keep in mind that the EKG app clearly states that it can’t detect heart attacks, and that the app offers lots of in-your-face opportunities to not just make note of symptoms but to contact emergency services.

I’ll bet you a cup of coffee that Apple has code that would do a danged good job at detecting heart attacks in all sorts of forms. But I’ll bet you a nice dinner that it won’t see the light of day for years, if ever.

I agree that it would be wonderful indeed for the watch to be taking continuous EKG readings and interpreting them with all the wisdom of a long-tenured cardiologist — and also that every little step in that direction is a good thing. But I can’t get upset at Apple for taking baby steps with respect to the automatic diagnosing features.

Another way to think about it: would you trust me as a completely uneducated patient to be able to tell the difference between “PANIC!” and “arm jiggled a bit plus wrist is sweaty”? And if you would prefer your patients to check with you in such circumstances … wouldn’t you also want them to be sending you their EKGs rather than relying on the watch to tell them whether or not to panic?

b&

 

[Dave00]

I'm aware that Apple doesn't claim to detect anything more than atrial arrythmias and bradycardia. A single-lead EKG could never detect a heart attack, even if analyzed by a trained physician - you'd need a multi-lead, preferably 12-lead, EKG for that. But arrhythmia can be determined from a single-lead EKG, and is regularly correctly interpreted by an EKG machine with processing power on par with a graphing calculator.

Atrial fibrillation is actually much harder to see than a ventricular arrythmia. To give you an idea, normal sinus rhythm looks like what you see on every EKG icon, including the ones Apple uses for its apps. Ventricular fibrillation looks like a sine wave. The only hard part is that someone with a tremor or other rhythmic movement can create a pattern that looks similar.

Perhaps the issue is a practical one, in that people in chronic atrial fibrillation are easy to find and test on. In contrast to people with ventricular arrythmias, which we generally try to fix right away. But that could be accounted for by testing the software separately, feeding it tracings of arrythmias to judge its accuracy.