Kardia reading

[LizLancashire]

I'm in afib just now - started at 3 am yesterday morning. I've noticed that if I do two kardia readings in quick succession, a minute between each, then the second one is much lower. This morning first one 141 bpm, second one 88 bpm. Has anyone else noticed this or anyone have an explanation?

[Jalia]

When you're in AF your heart rate is haphazard, swinging from high to low and everything in between. You have simply captured an average of the low and the high at the time of that recording. Leave the Kardia alone for a while. No great mystery!

[mav7 in reply to Jalia]

LizLancashire Good advice from Jalia. Are you taking medication to control the high hr ?

[LizLancashire in reply to mav7]

I'm taking bisoprolol

[mjames1]

Do both of the Kardia ekg's say you're in afib? Or tachycardia? Or just the one with the higher heart rate?

Jim

[LizLancashire in reply to mjames1]

Both say I'm in afib..

[mjames1]

The only thing I can think of is that the ekg showing a low rate was when you were sitting or lying down and the one with the fast rate is when you are standing up or moving around. That would be a normal response if rate not sufficiently controlled by drugs. If it's not that, I'm baffled. What does your doctor say?

Jim

[LizLancashire in reply to mjames1]

I've just noticed it yesterday and today with this latest episode so haven't spoken to anyone else about it. All the readings were done sitting in the same position with second reading immediately after the first.

[mjames1 in reply to LizLancashire]

What about the ekg showing the slow rate. Are the intervals similar throughout, or does it change at a certain point? Possibility exists that you were coming out of afib on the slow ekg but there was enough irregularity for Kardia to call it afib. Feel free to post both ekg's here for us amateur sleuths

Jim

[LizLancashire in reply to mjames1]

Thanks Jim but I wouldn't know how to post them on here.

[Singwell in reply to LizLancashire]

Just take a screenshot from your phone and use the picture icon below to upload it.

[Speed]

Currently, a typical episode of AF for me (every few weeks) has readings on my 2 lead Kardia showing approx 115 bpm “tachycardia” for the first few hours, changing to 85 bpm “possible AF” for several hours before returning to NSR within 5-10 hours. During an episode I usually take 2 x 50mg PIP Flecainide but sometimes need a further 2. Can’t be sure the flecainide causes the return to NSR as never left it without to see if returns to NSR on its own after a period.

When you take a 3rd and 4 th / subsequent readings, fo these follow a trend or fluctuate?

[gsd01]

The Kardia user manual shown on the British Heart Foundation page bhf.org.uk/-/media/F3570E1C... quotes the following.

Heart Rate

During your EKG recording, your real-time heart rate will be shown. When reviewing previous

EKGs, the average heart rate taken during that recording is displayed.

Heart rate is calculated as the time interval between consecutive heart beats; or more

specifically as the inverse of the time interval between consecutive R-waves in your QRS

complex. During an EKG recording, the current heart rate is measured from an average of this

inverse calculation over the last 5 seconds. For stored EKGs, the average heart rate is the

average of this inverse calculation over the entire 30 seconds of the recording.

I discovered this when I bought the Kardia 6l and discovered complete inconsistances

in the HR results.

One of my first strips read gave a 138 result but if you count the pulses (conveniently marked for you on the strip) they only added up to 108

From further extensive investigation I discovered the info above which would imply that if your AF heart rate has some variations during the scan you will end up with an inaccurate number which could be a fairly large incorrect result.

I also discovered that if you select a 60 sec scan which should give a more accurate picture of you HR it actually only gives you the first 30 secs of the strip doubled to give an even more inaccurate HR result.

I have a number of 60 sec strips that are completely wrong when compared to counting the actual beats. Always too high, example Kardia result HR 124 actual count 92.

I assume this is only a problem for AF particularly with a wandering rate and probably

gives close enough results for NSR. I wouldn't know as I have PAF but it makes the Kardia fairly useless for keeping track of actual AF heart rate numbers which is important if you are trying to keep your HR low. I stopped using the Kardia and was refunded.

[Jalia in reply to gsd01]

I've used Kardia..single lead....for many years, in fact I'm on my second model, but accept that the heart rate displayed cannot be 100 % accurate. It gives an idea of what is going on. I've almost always found the average given to be pretty much spot on.

[gsd01 in reply to Jalia]

All the strips I took were inaccurate between around 10% to20% out. If you are happy with an inaccurate readings then of course there is no problem but I was replying to someone who was asking about possible wrong readings!

[mav7 in reply to gsd01]

makes the Kardia fairly useless for keeping track of actual AF heart rate numbers

 Jalia  gsd01 or anyone Any idea or thoughts on how the Apple Watch would compare ?

[Jalia in reply to mav7]

I've never had an Apple watch so can't help there. Very difficult to obtain an accurate actual heart rate when in AF anyhow as it changes from second to second but you can see the numbers flashing across the screen!

Kardia is respected by the medical profession. I've been asked to send over a reading of my husbands AF from my device to cardiologist in the past. My own readings have been treated with interest in hospital setting as well.

[gsd01 in reply to Jalia]

All heart rates change from second to second to some extent, its called heart rate variability (HRV) in NSR this is usually a regular change and fairly small. You wont get any meaningful readings from the changing numbers displayed during AF on a monitor.

The meaningful number is the the number of beats over a 60 second period (heart rate is measured in beats per min) To assess your heart rate in AF you need to look at the ecg graph and a good device will accurately give the total number of beats.

You can then see the time interval between the shortest runs and the longest runs which will tell you during the average over one min. what the highest and lowest rates were, and how long each number of slow/fast beats lasted. This will then give you some indication of how much of a problem the AF is at that time.

Hope this helps

[Jalia in reply to gsd01]

I am aware of this. I don't feel its necessary to get too fixated on 100% accurate heart rates though. I know when I flip into AF and could estimate my rate fairly accurately without any device. Not surprising with 23 dccvs to date !

[gsd01 in reply to mav7]

Sorry I have no idea, I dismissed the idea of buying one based on reviews and the following from Apples website

Is Apple Watch reliable for atrial fibrillation?

The irregular rhythm notification feature on Apple Watch is not constantly looking for AFib. This means it cannot detect all instances of AFib, and people with AFib may not get a notification. If you're not feeling well, you should talk to your doctor even if you don't get a notification.14 Dec 2022

[LizLancashire]

Thanks everyone for your responses and I apologise for not replying to each one individually. After over 50 hours now in af I'm very tired. It's only a month since my previous 50+ hours af episode and when this one started I was depressed and didn't want it to be true which is why I took a second kardia reading immediately after the first hoping for a different result - which I got. Since then I've done 5 kardia readings and the same thing has happened each time. First reading 140+ bpm and second one 80+ bpm. The kardia now says Possible AF so hope I'm coming out of it now.

I'm on bisoprolol and edoxaban now but have an appointment at the hospital mid May for heart stress test with a vew to taking daily flecainide until it's time for a second ablation . I've hesitated to have a second one as I had a tamponade during my first.

Thanks again everyone for your interest and advice.

[johnMiosh]

Are you fetching the Kardia from somewhere, sitting down and doing the test straight away. Then waiting a minute while sat before the second test?

[LizLancashire in reply to johnMiosh]

No, kardia is in bag beside the sofa so I sit down and then take reading(s).

[Anniewee6]

Afib is an irregular heartbeat and that’s what your Kardia is showing.

[LizLancashire]

After 58 hours Normal Sinus Rhythm 76 bpm

Thanks everyone and enjoy your weekend.

[KootenayTrails in reply to LizLancashire]

58 hours … I’m sorry you’ve had to endure that! I can barely handle 5 or 6 hrs at a time, and have only gone 12 - 20 hrs. My EP (Canada) has said for me to go in for a cardioversion after no more than 10-12hrs in AFib, and sooner if I feel I might faint. I’ve had 6 cardioversions now, and it only takes 2hrs from time I get to Emerg to leaving for home. EP says ablation has a better chance of working well if paroxysmal AFib isn’t left too long. It seems UK advice is different though, I’m noticing? Wondering at the difference in philosophy … or is it availability / busy Emergencies there? At any rate, Hope your next ablation holds for a long time, so you get some normalcy back - Cheers!

[LizLancashire in reply to KootenayTrails]

Thank you Kootenay Trails. After 6 hours unbroken sleep (very rare) I feel like a new woman. My afib episodes used to be 12 - 15 hours but this year 4 episodes of 40 - 58 hours. Cardioversion has never been mentioned in my A & E visits. I've been told not to go unless I feel dizzy , breathless, chest pain. My last visit I was on a trolley in the corridor so I was determined to try and deal with it at home this time.

[Tomred]

Thats the nature of afib to me

[Letofeyd]

That is AF in a nutshell.😏

The Kardia hr reading is an average.

AF is not constant rate - it is an erratic heart rate, with periods of closely clustered bears and sometimes long lags between beats. If the 30 seconds you tested just happened to hit a cluster period, the average will be high. If the next reading had more long gaps or regular spaced beats, the average will be lower.

[Lenaropes]

All monitors show only a 30 second capture and then average. It is random and as other have said this is how AFib is. The rate changes rapidly up and down and this is a normal variation.