Interpreting Kardia ECGs: I am still... - AF Association

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Interpreting Kardia ECGs


I am still recovering from my second ablation in four months. 7 weeks on the heart is settling but still tired and lacking energy.

The readings I get using the cardia seem to flip about. First reading may show' possible AF' but retaking the reading then shows 'unclassified'.

I found this website run by Travis Van Slooten which did a review of the Kardia:

living with artialfibrillation/1961/alivecor

It suggested the following explanation: inaccurate or misleading filter.

'The AliveCor app is able to indicate if you’re in afib or not because of a filter. This filter is based on an algorithm. Unfortunately, algorithms aren’t perfect. As a result, there are times where the filter will indicate “possible afib” when you’re not in afib at all. If you’re not in afib but your ECG isn’t normal either, the filter will indicate “Unclassified.” Both scenarios aren’t ideal as it can cause a lot of stress and anxiety for an afibber:)'

If repeating the ECG immediately shows a different result from 'possible AF' then you are probably not in in AF.

I found this helpful because my ECGs are all over the place with lots of PVCs and PACs. I know that the scar tissue is still forming after the ablation, so hopefully my heart will settle.

8 Replies

I have great difficulty getting a sensible reading from my original Alivecor because my fingers are dry and caloused from working with metal. If I do ever use it I get a lot of what they call artifacts which are rogue readings. Using hand sanitiser first apparently helps.

I suggest you get someone to hide your Kardia! This is interesting and useful information but you should also look up 'biofeedback' - if you are constantly looking for problems you can actually cause them. Otherwise try to limit use to a time when you can tell yourself without Kardia that you are in AF so you have a record for your EP. I hope things settle down soon.

Slim2018 in reply to Buffafly

My daughter, the doctor to be, has said something similar so to appease her I now have a finger pulse and oxygen thingy-me-bob and only use the Kardia once a week to review things. I showed her one reading which I thought was dodgy and she said “no perfectly normal” so my little bit of knowledge wasn’t doing me any good. That said, love the Kardia and wouldn’t be without it.

Did you see the post about the Apple Watch - apparently it is better than the Kardia.My Kardia was often confused by my ECG post ablation.

outofsynch in reply to S11m

Thanks I will check out the post.

S11m in reply to outofsynch


I am aware that there is more to interpreting the single trace output from a Kardia than just accepting what the algorithm tells you. There is a useful section on their web site to help 'read' the output trace, and teaches quite a lot about the various parts of the waveform. However, the underlying essence of AF is that the beats are not occurring in a regular rhythm, and that can be established by printing off the output and physically measuring the spacing of the waveform. Alternatively, load it up onto your computer and magnify the trace. AF then becomes quite obvious to me.

I frequently get an 'Unclassified' report, mainly due to artefacts introduced by such things as moving muscles, noisy environment, electrical events or nearby electronics. These can fool the algorithm, but not hide whether the beat spacings vary in an AF way.

outofsynch in reply to momist

I'll check out their website. Thanks

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