Apple watch AF summaries

[OldJane]

I recently acquired an Apple Watch, a supplement to my Kardia, I want to catch episodes as I contemplate the offer of a second ablation. My AF journey which started with a severe viral cough has been one of intense episodes, 8-12 hour very symptomatic monsters pre ablation and brief ones since - one hour episodes one each year until this year when I had a five hour one. I wondered if I was having short ones which I wasn’t noticing. My Apple summary for last week was “AF less than 2% of the time”. This is all new to me. As an ex reader of research such a low number may be meaningless- or is it? I haven’t noticed any episodes. It doesn’t tell me when these episodes were simply “over the last week”. Any thoughts?

[mjames1]

Apple Watch will never say "afib 0%."

"AF less than 2%" is the best you can get. so nothing to be concerned about.

It will also always say "over the last week"

All good.

Jim

[Buzby62]

Apple Watch will not capture all your AF, it only checks periodically in the background. 2% or less is what someone who has never had AF would get if set up for AF History as opposed to AF Alerts.

I’ve replied to several posts on this previously, if you click on my profile and then click on replies and scroll down you will find them.

Hope this helps

Edit: Link for you support.apple.com/en-gb/HT2...

[Autumn_Leaves]

The Apple Watch doesn’t monitor continuously. It makes regular ‘spot checks’ on your HR. If I remember correctly you have to be in AF for at least 1 hour for the watch to pick it up, and if your HR is too high in AF it may not work — which I know is counterintuitive, but I’ve had that warning from the watch during fast AF. The watch is not a medical device. It’s very useful but if you are wanting the equivalent of a 24h ECG, that’s not it. If it doesn’t pick up AF at all you’ll still get the “less than 2%” summary every week. If you have one short episode of AF, you’ll probably get the same.

My cardiologist told me the watch is not an ECG, but the Kardia is. The problem is, you can’t wear the Kardia whereas the watch is on your wrist already and it’s so easy to check what’s happening on the ECG app. In practical terms, the watch is just as useful as the Kardia in that it can make a reliable rhythm strip, even though it does throw up some false positives, but if you can learn to read the trace you will be able to recognise the difference between AF and various ectopic patterns. I think with these devices we just have to be realistic.

[bassets]

If it helps mine says less than 2% too. I take this to mean no AF episodes during the week x.

[Foxglo]

My comment isnt about apple watches. I use mine to catch any fast episodes to show the cardiologist the ECG which I find helpful. When I was having a few fast episodes or lots of Ectopic I had a Zio monitoring patch that sticks on near your collar bone. My cardiologist arranged it. I can't remember if they are 2 or 4 weeks. It records all rhythm differences. I found this a excellent tool to give an accurate record as well as being super easy and comfortable.

[bigbearatthecave]

My Apple watch says I am in Afib all the time and my Doctor has confirmed this. However if you look at your watch or any of these devices all the time you will end up in the loony bin or under a shrink as it will drive you mad. Check occasionally is fine otherwise wait until your body tells you you have a problem. I have gone back to wearing my old mechanical tag watch and life is much less stressful

[Autumn_Leaves in reply to bigbearatthecave]

I’m more inclined to let it run in the background and let it do its thing. I don’t check the Heart app that much and only use the ECG if there’s a reason, if I suspect AF or I’m having a lot of ectopics. They also tell the time 😂

But yes, for some people these watches will do their head in.

[Hidden in reply to bigbearatthecave]

To be honest, I have the opposite result from my Apple watch. I find it immensely reassuring that I can check on what's going on at any time, and it's just confirmed that my understanding of how my body is feeling at any given time is accurate. But I understand that it's not for everybody.

[Autumn_Leaves in reply to Hidden]

I also find the watch reassuring. If it wasn’t for the watch I wouldn’t have been able to catch my first (known) episode and hence been able to get a referral for a diagnosis of AF. The ability to self monitor is very helpful. Overall, it’s an invaluable tool.

[FanOfPatterns]

I investigated the apple watch for AFib. It doesn’t monitor your heart all the time unless it is aware you are exercising. They don’t provide a summary of when they actually sampled your heart rate. If they don’t detect anything, they put in a placeholder statement that AFib may have been present for less than 2% of the time.

I have wondered about replacing my borrowed fitbit Versa 3 with an apple watch. I have decided no. I decided to get a KardiaMobile 6L to get some ECG info when I want.

I would love to see some independent comparisons of different monitoring devices and their features from a consumer and medical perspective. Anyone seen anything like that? Links would be great!

[kitenski in reply to FanOfPatterns]

I've been looking into this, if you turn AF History on then the AW takes a HR sample every 15 mins regardless of wether you are exercising or not. You can see this by looking at, your heart beat, or HRV readings. With AF history on it samples every 15 mins, with it off it samples a lot less.

[Ppiman]

I might be wrong as I don’t use my Apple Watch for constant checking of AF, but I thought that this only picked up pulse irregularity. If that’s so, I suppose these could be either ectopic beats or AF. The AF app, needing to be touched for 30 seconds is different and checks for irregularity along with a lack of P waves.

I think I also recall reading that the watch only checks the pulse every so often to preserve battery life.

Steve

[Autumn_Leaves in reply to Ppiman]

There is a setting that you can turn on or off if you have diagnosed AF. I’m not sure how it works, whether it takes more sample readings or more spot checks or for longer periods. I’m sure the info is online somewhere. As my cardiologist told me, it’s not an ECG. As you say, it’s more of a pulse reader but it can still be very useful and informative. Having said that, I’ve never had the watch alert me to an AF episode just passively monitoring in the background. It has correctly identified AF when using the ECG app, but it’s also incorrectly identified ectopic rhythms as AF. The tracings are useful to print out and take to appointments too.

[Ppiman in reply to Autumn_Leaves]

My Kardia did similar a couple of times labelling ectopic beats as AF but so far the watch has been accurate. I guess your cardiologist was simplifying as both do detect the heart’s electrical signals. The pulse app on the phone is different and measures blood flow on the wrist optically (I think).

Compared with a professional multi lead ECG monitor I suspect both are more like sophisticated toys. 😳 I do like gadgets though!

Steve

[Autumn_Leaves in reply to Ppiman]

I found the same with the Kardia. Or ‘inconclusive’. My own opinion of the apple watch is that it’s very useful. The ECG app can make reliable recordings of AF, PACs, PVCs etc. If you can learn to spot the differences between AF and the various ways ectopics present then you can identify AF episodes with more accuracy, as opposed to being freaked out by false positives for AF. If you can make some print outs and take them to an appointment, the opinion of someone with an experienced eye is invaluable especially if they can explain why it’s not AF even though the algorithm says it is. I have found the watch to be very, very helpful overall. It can’t give the information a 12 lead ECG can, nor can it stand in for a 24h Holter, but it’s a very convenient and easy way to record arrhythmias and HR. I reckon it’s helped a lot of people get a diagnosis a lot earlier and in some cases, probably alerted quite a few people to their asymptomatic AF.

[Ppiman in reply to Autumn_Leaves]

And saved lives, I guess, given that a stroke is, apparently, the first some sufferers even know that they have AF (a truly shocking thought for me).

Steve

[Buzby62 in reply to Autumn_Leaves]

support.apple.com/en-gb/HT2...

[Autumn_Leaves in reply to Buzby62]

Thanks. I’m sure that will be useful for the people who want to use that facility.

I already have that feature up and running. It’s not that I don’t know how to switch it on, It’s more that I don’t know how and what it does to monitor AF in the background, in the technology sense. It’s never picked up any of my AF episodes so far.

[Buzby62 in reply to Autumn_Leaves]

I do get higher numbers when I’ve had AF, like 5%, but I don’t know if that is picked up in the background or because I always check a few times with the ECG app during episodes. The background heart rate checks using the green light are less accurate than the ECG app using your finger to create an electrical circuit. You can also use the Heart Rate app with your finger for more accuracy. For the background checks to indicate signs of possible AF I believe it relies on Heart Rate Variability being high while you are at rest when it checks periodically.

From the link I posted earlier (What you should know at the bottom):- Apple Watch only checks for signs of atrial fibrillation periodically. AF History may not find every instance of your irregular rhythm.

Here’s another link on how the heart rate is monitored and the two methods the watch uses.

support.apple.com/en-gb/HT2...

Hope this is helpful.

[Autumn_Leaves in reply to Buzby62]

Thanks.

Definitely the HRV spikes a lot during AF, but it’s also prone to spike a bit if there’s a lot of ectopics going on. Overall, very useful.

[Buzby62 in reply to Autumn_Leaves]

That’s interesting, as far as I know I don’t get a lot of ectopics, I think it was about 5 in 48 hours when I had a holter about 18 months ago.

My watch reports high HRV when in AF and that’s the only time I see it which makes sense.

I agree, I find it very useful as long as you’re aware of the limitations as mentioned and don’t let it cause more anxiety to feed the AF.

[Hidden in reply to Autumn_Leaves]

I have been notified by my watch that I was in AF but that was a while into the episode.

[LaceyLady]

My consultant was impressed with my Kardia 1L and went and bought his FiL one and recommended them 😜 I’ve an Apple Watch and quite pleased with it. I did get a top model one and had it now about 2yrs, I ‘think’ it has alerted me to being in AFib once.

[Autumn_Leaves in reply to LaceyLady]

It was my consultant who recommended the Kardia. I would say as a 1L ECG it’s excellent, but the Apple Watch is so handy.

How did you get on with the haematology appointment? Weren’t you due to see him on the NHS?

[LaceyLady in reply to Autumn_Leaves]

😤 The lady dr quoted the men’s limit, I’d taken in copies of the Haemochromatisis UKs booklets for Professionals 😜 Say I’m borderline She couldn’t argue with that 🙄 Got another appointment in December by phone 🤦🏼‍♀️

Since had spot with consultant in Gastroenterology, HE was loads better, still no venesection but took raft of bloods taken nearly 8 wks to be told them! Apparently I’ve inflammation somewhere 🤷🏼‍♀️ And wants me to have re-tests. I have to wait as I had my pinky caught in car door and 6/8 stitches 😳 Healed. He’d said get bloods in few Wks 🤷🏼‍♀️

[Autumn_Leaves in reply to LaceyLady]

Inflammation can increase ferritin levels, and far better to get it down by letting it resolve naturally rather than having to go through the dreaded venesection, if you can. Pinky injury sounds excruciating. Injury can drive up inflammation, and anything like arthritis flare ups can do as well. I was scheduled for venesection last month but still wiped out with post Covid fatigue so I’m putting it off for a while.

[LaceyLady in reply to Autumn_Leaves]

Yes, this is problem, I’ve permanent head n neck pain, lower back and ruddy foot pain 😵‍💫 So, what to do!

[Autumn_Leaves in reply to LaceyLady]

I think it’s the flare ups that you have to watch. Keep an eye on your white blood cell count. It will rise if you have an arthritis flare up, or an infection and is quite a good indicator of inflammation even though it’s not a specific test for it.. Also if you have your CRP/ESR checked, these can be raised if you have an inflammatory condition. If these are all low or normal then your ferritin is a reliable indicator of your iron stores and isn’t being increasesd by inflammation. So you can tell from the other tests whether raised ferritin is inflammatory or iron overload.

[Mollybobs]

My Apple Watch has picked up every AF episode I’ve had, I wouldn’t be without it!

If you look in AF history you will get a weekly breakdown.

Check heart rate variability daily breakdown too, this will show very high peaks when in AF, I never got those peaks when I had the SVT.