Kardia Mobile Interpretations

Been using it for the last 2 yrs and seems it can never make up it's mind, calling an episode Afib during one reading, and then Supra Ventricular Ectopy the next (30 seconds later).

Even when I showed it to my docs (cardio, EP etc) they all say "does not look like Afib to me, I can see the P waves".

When I used a Holter at the same time, turns out none were Afib (all PACs), even though Kardia labeled them as Afib.

So the question is... what's the point of having Kardia lol. Am I the only one getting these inconsistent results?

A lot of ectopy can fool not only the Kardia but many doctors as well. And it can reach the point that there's really no functional difference between a lot of ectopics and afib, so the distinction isn't really meaningful.

Atrial fibrillation IS ectopy, and it is part of the irregular beats comprising 'supraventricular tachycardia'. But, if there's a P wave, it ain't AF.

It seems these wearable devices are hampered by having to rely on one or two leads, and not the 8/10/12 leads of more sophisticated devices (costing hundreds of dollars more to boot). I would put all my money on the Holter, personally.

My own Samsung Galaxy 4 would sometimes show 'undetermined irregular rhythm, consult your doctor'. The resulting ECG was horrible, all jagged, looked scary. But it didn't look like AF either, and I couldn't blame the twin lead Galaxy for that.

Thank you. Yes I am thinking of getting Wellue's 12 lead ECG... it's tiny, can be used as an instant ECG or 24hr Holter, and it will do a much better job than anything else out there.

I don't believe the Kardia can digitize p waves and use their absence as part of the analysis. I think what they do is look at beat to beat variability. A string of PAC's with the PAC's each being followed by a compensatory slow beat will look like there is very large beat to beat variability. If the PAC's don't have the compensatory beat, then it will look more regular and likely classified as SVT. Though I have a Kardia, I also use the old school technique of just looking a beat to beat time in milliseconds vs clock time or beat to beat heart rate vs time. The PAC's with compensatory beats look very different than afib, even though they both have a large beat to beat variability. There is a lot of visual regularity in the PAC's that is absent from the afib. For subscribers (as I've had mine since 2014, I'm grandfathered in on the subscription) Kardia provides a HR vs time graph in their PDF output. The only thing is that graph has both beat millisecond time on one Y axis and HR in BPM on the other. The millisecond (ms) time axis is linear and the BPM looks almost like it is logarithmic as use the linear ms values and convert to BPM. I can look at a whole night's worth of data in a minute and see if there is any afib.



Edited 2 time(s). Last edit at 09/19/2023 06:10AM by GeorgeN.

Interesting, you definitely know a lot about EKGs! Thank you very much for your insights, I appreciate it.

I concur with those answers.
My own device (not Kardia) never says "AFib". It mostly reads and mesure R-R variations, and says "suspected irregular beat interval" (in this case, it's usually AFib) or "suspected occasional short beat interval" (in this case, it's usually just some ectopics).
It does not see "p" waves.
In some cases, there are lots of PACs with some normal beats here and there. As the device does not take "p" waves into account, it just sees irregular R-R intervals.
As said, AFib looks like a succession of PACs. When I've long runs of PACs, I feel them like AFib.

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WhyMe
Interesting, you definitely know a lot about EKGs! Thank you very much for your insights, I appreciate it.

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Pompon
I concur with those answers.
My own device (not Kardia) never says "AFib". It mostly reads and mesure R-R variations, and says "suspected irregular beat interval" (in this case, it's usually AFib) or "suspected occasional short beat interval" (in this case, it's usually just some ectopics).
It does not see "p" waves.
In some cases, there are lots of PACs with some normal beats here and there. As the device does not take "p" waves into account, it just sees irregular R-R intervals.
As said, AFib looks like a succession of PACs. When I've long runs of PACs, I feel them like AFib.

Here are some visuals. Again these are heart rate vs time graphs, NOT ECGs.

I coached one member here to use the combination of an app, Polar H-10 heart rate strap & some old Polar software to do long duration monitoring with beat to beat heart rate data recording. The member had an ablation not long ago and recently contacted me to help interpret a recording. Basically it was a whole bunch of PAC's. If I zoomed out, you'd see relatively short PAC activity in the midst of a lot of NSR. I'm sure the PAC's didn't feel good, but the ablation was still working.


In this graph, there are many PAC's (which show as fast beats) and most are followed by slow beats or compensatory beats. These are actually normal beats, but show as slow as they start "early" as the PAC is fast. Not all PAC's are followed by a compensatory beat. If you are feeling this with your pulse, it might still feel pretty random. Marked with arrows, there are some completely "normal' beats.



In this graph, afib is shown on the right, along with one isolated PAC and an isolated PVC. You can see how random it appears.


Even with an ECG, unless you plot out the beat length times, it can sometimes be hard to see just looking at the ecg. If there are more normal beats than what is shown in my example above, it is easier to see (or feel) the more isolated PAC's.

The first graph is from a member here that had a recent ablation. The latter two were from this pdf that was sent to me years ago from a member in the UK. These are all heart rate vs time graphs. Sadly, for his sake, he captured many different rhythms.

[www.afibbers.org]

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WhyMe
So the question is... what's the point of having Kardia lol. Am I the only one getting these inconsistent results?

In most cases, Kardia's "determinations" are quite accurate, however various scenarios can confuse it. This is the same with the automatic determations found on the 12-lead ekg machine found in your doctor's office. That's why most ep's totally ignore automatic determinations on their 12-leads and simply look at the ekg itself for analysis.

So what's the point of having a Kardia? The point is to have a device that will generate single or six lead ekg's at home on demand. If you can't analyze the ekg yourself, then send it to your ep. IMO an invaluable device for most of us with afib.

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mjamesone
If you can't analyze the ekg yourself, then send it to your ep. IMO an invaluable device for most of us with afib.

From a single lead ECG, you can manually create HR vs time graphs like I've plotted and see the same differences. Kind of a pain to do it manually (why I like doing it with an RR (beat to beat) recording heart rate monitor & software). However I have done it for some folks (and taught them how to do it for the future) where the automatic interpretation was suspect. Someone who looks at a lot of ECGs can see the patterns visually without creating the HR vs time graphs.

Ok then...what do you think about this one...Afib, or Sinus Supra Ventricular Ectopy? Keep in mind all my episodes are at normal HR.

Then I'll tell what Kardia said

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WhyMe
Ok then...what do you think about this one...Afib, or Sinus Supra Ventricular Ectopy? Keep in mind all my episodes are at normal HR.

Then I'll tell what Kardia said

I've annotated the graph. Normal, PAC, Compensatory beat. Rinse & repeat. The numbers on the ECG are numbers of small boxes between beats. You can do this yourself. Numbers on the X Axis are cumulative seconds. You can also see this pattern without counting as the patterns happen to stack on the ECG printout.





image uploader

Excel sheet: [docs.google.com]

Seconds = Small box count / 25
Cumulative seconds = cumulatively add seconds going down the page
Heart Rate BPM = 60 / Seconds

Small Box, Seconds, Cum Sec, Heart Rate
22	    0.88	0.88	68.2
16	    0.64	1.52	93.8
28	    1.12	2.64	53.6
23	    0.92	3.56	65.2
16	    0.64	4.2	93.8
29	    1.16	5.36	51.7
23	    0.92	6.28	65.2
16	    0.64	6.92	93.8
29	    1.16	8.08	51.7
22	    0.88	8.96	68.2
16	    0.64	9.6	93.8
28	    1.12	10.72	53.6

Edited 6 time(s). Last edit at 09/26/2023 02:48PM by GeorgeN.

Oh wow, thank you very much for doing this, I really appreciate it!

Ok good to know. See, Kardia called it Afib, but several Drs told me this is not Afib. Then Kardia sometimes calls it Supra Ventricular Ectopy.

So I am obviously very glad it's not Afib...but I just hate having these every single day, in between my meds dosages. I had my ablation with Natale last month and I am very discouraged I am having these daily with no sign of relief.

Are these "unablatable"? Is this my life going forward? Thanks again for all your help.

Math in post above was corrected.

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WhyMe
Ok good to know. See, Kardia called it Afib, but several Drs told me this is not Afib. Then Kardia sometimes calls it Supra Ventricular Ectopy.

Since the way Kardia looks at things, you can see there is quite a bit of variability, hence why it may call it afib. However when you look at with your eyes, you can see it is NOT irregularly irregular as afib is. It has a pattern.



Edited 3 time(s). Last edit at 09/26/2023 02:52PM by GeorgeN.

Those PACs can be annoying, discomfortable or a cause of stress, but they're nothing to really worry about.
At least if you don't have them all day long. If you do, it's maybe a little too much, and I think you might talk about them to your EP.
Don't forget you're still in your blanking period. PACs may subside during the weeks to come.

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GeorgeN
Note, my math is off for seconds above by a couple of orders of magnitude. Doesn't change the pattern or my interpretation. I will correct my post and the spreadsheet later in the day


Ok good to know. See, Kardia called it Afib, but several Drs told me this is not Afib. Then Kardia sometimes calls it Supra Ventricular Ectopy.


Since the way Kardia looks at things, you can see there is quite a bit of variability hence why it may call it afib. However when you look at with your eyes, you can see it is NOT irregularly irregular as afib is. It has a pattern.

Thanks. Yeah, I see what you are saying... it's like 1, 1 2, 1, 1 2, 1, 1 2....

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Pompon
Those PACs can be annoying, discomfortable or a cause of stress, but they're nothing to really worry about.
At least if you don't have them all day long. If you do, it's maybe a little too much, and I think you might talk about them to your EP.
Don't forget you're still in your blanking period. PACs may subside during the weeks to come.

Thanks. Yea... trying to stay positive. Deep breaths...

Sometimes the data is very noisy and I have to keep restarting data collection with the Kardia Mobile to get a clean EKG. Is that typical? I have a 6L, and sometimes I have to switch from single lead to 6-Lead to get a decent EKG.

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kenn_green
Sometimes the data is very noisy and I have to keep restarting data collection with the Kardia Mobile to get a clean EKG. Is that typical? I have a 6L, and sometimes I have to switch from single lead to 6-Lead to get a decent EKG.

Yep, definitely common. A Kardia is no different than a real ECG. You need to be sitting, have the Kardia on a surface in front of you, and remain perfectly still. It's also advisable to be away from large appliances like refrigerators, TVs, etc.

Been away for while. My concern is that doctors either just want to put you on meds, or burn away part of your heart, and don't want to look for underlying causes, too much work? I'm not happy being on xarelto and Metoprolol Tartrate. My reps at the gym are noticeably down for upper body and I can't donate blood, which was something I felt really good doing because they can give my blood to babies, not all can be used. I keep reading people talk about an irregular heartbeat. When I have my episodes, the waveform looks fairly uniform to me (see attached) given the quality of a Kardia Mobile. Do the cardiologists base the AFIB diagnosis on this or do they have data I don't see? I have a impinged shoulder hurting my sleep (almost done with PT and a lot better than a month ago), and diagnosed to have sleep apnea with an appointment Nov 14 to get a cpap. It seems like I have the high pulse after a night with lousy sleep. I don't think I have ever been diagnosed with AFIB without the high pulse and I think my heart looks good in all the standard tests. I have a 100mg caffeine "healthy energy drink (Zipfizz for Pure Boost)" in the morning and on the days with the high pulse usually go back to a low pulse in the 50s in maybe 30 to 60 minutes.

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kenn_green
When I have my episodes, the waveform looks fairly uniform to me (see attached) given the quality of a Kardia Mobile.

There is variability. Suggest you do the exercise of counting small boxes between beats like I did above. Then plot by hand or in Excel as I did next This is essentially what Kardia is looking for. Your docs will typically use a 12 lead ECG and have more data to base it on, including the presence or absence of "p" waves before the QRS. In my heart rate vs time examples above you can see the difference between a bunch of PACs and afib, even though both have an irregular beat.

On apnea, sometimes taping your mouth at night can solve the problem. See this post as well as this one for resources.



Edited 1 time(s). Last edit at 10/15/2023 07:20AM by GeorgeN.

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kenn_green
Been away for while. My concern is that doctors either just want to put you on meds, or burn away part of your heart, and don't want to look for underlying causes, too much work?

Yes, too much work. Discovering the underlying cause of afib is Nobel Prize territory. The research into the cause(s) has been going on for decades, so expecting your doctor to make a breakthrough is an unrealistic expectation. There isn't a single person on the planet whose doctor has succeeded in doing so.

Hi George.
I didn't want to highjack the post from Rich63.
After seeing the your graphs etc and this topic I did an ECG on my Withings Scanwatch.
Yesterday I was doing some hard work in my yard. Hot day and sweaty.
I had some ice cream in the afternoon even though I was hungry.
Then a sweet fizzy drink (soda) after dinner.
I was feeling worn out but too much sugar is not the answer.
Fell asleep later that night the woke up after an hour with high heart rate.
I thought I had done well that day not to bring on an episode.
Ah well .....
What do you see in my ECG?
PACs and PVCs and ectopics etc
cheers

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Steven
What do you see in my ECG?

Afib with one PVC.

Thankyou Carey. It is all so complicated. Maybe in the future doctors will edit the ECG to rectify Afib. Like digitally editing music etc. cheers