Apple Watch Accuracy

[Jafib]

I know there has been some discussion on here about Apple Watch (AW), Cardia-Mobile, etc., however, there is a specific point I would like to address. I regularly check blood pressure, hr and rhythm since having SAVR back in early September and my AW almost always (99%) indicates I am in NSR. Now, when I go to the doctor with my white coat syndrome and skyrocketing bp and hr, they say I am in afib or aflutter. I even sent a note to the doc, and he said that the AW is generally accurate when detecting afib/aflutter vs NSR. I do not have enough experience or know how with the AW to get reports from it, although I believe someone mentioned that was possible. So, my question for you - what level of confidence would you place in the AW to detect NSR v. arrythmias?

Thnx

[Buzby62]

From the ECG app using the electrical sensors I would say very high confidence in my experience but you have to do an ECG manually to catch any irregularities when they are happening.

From background heart rate checks by the optical sensors low confidence in picking up all irregularities and will probably miss short episodes. Also the heart rate shown instantaneously can be inaccurate while in AF.

Apple support links

support.apple.com/en-us/120277

support.apple.com/en-us/120276

Best wishes

[Hallju]

My electrophysiology NP has great confidence in my AW. My pacemaker only picks up high heart-rate afib (it’s an older model that can only be adjusted so much), but I gave her the readings from my AW and she is very comfortable using that data to schedule me for another ablation if I am ready to do that again.

[Moose09]

For some reason my Apple Watch did not and still does not reliably pick up my afib or other arrhythmia (PAC / SVT). I am only in sinus for 4-8 hrs a day as confirmed by previous 24 EKGs, but it consistently tells me I am in sinus 95% of the day. Both my cardiologist and EP rely on my Kardia.

I have found that the Apple Watch HR variability measurement is useful in telling me how my arrhythmia is doing, especially as a trend.

[beach_bum]

check the fit of the watch. If it’s too lose, even a bit, it can give false of irregular readings.

[KentAndrew]

St Bart’s hospital in London conducted a medical study for post ablation patients.

The team loaned Apple Watches to the participants, with the idea that instead of reporting to a Hospital or Surgery for an ECG, the patient could use the watch.

Each time the Apple Watch alerted that the participants had a AFib episode they emailed a pdf of the ECG trace and a member of St Bart’s mailed back - in my case - confirming that I was in AFib each time.

I understand that this study is undergoing peer review for publishing.

[browng]

there is an interesting statement in one of the above Apple articles:-

These notifications are not designed for people who have been diagnosed with AFib.

[Buzby62 in reply to browng]

Hi, here’s another link to the alternative setup when diagnosed with AF. It’s called AF History and when enabled that disables the notifications.

support.apple.com/en-gb/108375

I will say that in either mode it will not capture all AF as it says in the articles.

Best wishes

[mav7]

Thanks for posting those articles,  Buzby62

So as I read the articles and your comments, the Apple Watch most likely would not project correct heart rate readings for a person in persistent or permanent afib ?

My interest is monitoring my heart rate continuously even while sleeping. Not concerned with the EKG.

[Buzby62 in reply to mav7]

Hi mav7

My understanding is that the EKG (ECG in UK) is the only reliable measurement when in AF as it measures an average electrically over 30 seconds rather than optically instantaneously (a few seconds). I guess the optical background HR checks can give a good indicator of trend changes but I wouldn’t rely on the actual rate recorded at any single point. It’s the average HR that matters in AF.

I also found that the optical sensors can miss some of the rogue AF beats if they are a weaker pulse. Like everything AF it will be different for everyone I guess.

Best wishes

[mav7 in reply to Buzby62]

Thanks !