EKG question

When looking at an EKG, for example taken from a Kardia device, is the most important thing consistency with the intervals between the tallest peaks? (I think it's called the "RR interval".) Or does the consistency with the "stuff" in between carry alot of weight?

With Kardia, It seems that, generally, if the RR intervals are consistent then the EKG is considered "normal", even though there may not be 2 consistent and clearly defined humps between them. (I think "T" and "P".)

Any thoughts on this?

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cirenepurzalot
When looking at an EKG, for example taken from a Kardia device, is the most important thing consistency with the intervals between the tallest peaks? (I think it's called the "RR interval".) Or does the consistency with the "stuff" in between carry alot of weight?

With Kardia, It seems that, generally, if the RR intervals are consistent then the EKG is considered "normal", even though there may not be 2 consistent and clearly defined humps between them. (I think "T" and "P".)

Yes, consistent RR intervals are important. With afib, the intervals are very irregular.

If you have a two contact Kardia (1 lead) and holding each contact in each hand, this is considered "Lead I." Lead I does not display P waves very distinctly. You can get a larger amplitude by putting the left contact around your hip or knee, holding the other contact in your right hand.

"For a Lead II ECG, the left knee should contact the electrode closer to the top of the
smartphone or tablet and the right hand should contact the electrode closer to the
bottom of the smartphone or tablet. " source p 9.

See about 1/2 way down here.

See afib on a Kardia here.

If the R-R intervals don't vary much, it can't be AF because the very nature of AF is an irregularly irregular pulse, and the R-R intervals determine whether it looks and feels regular or not. (And yes, there is such a thing as regularly irregular. Bigeminy would be an example.) Honestly, I can diagnose AF as accurately as a Kardia by just feeling your pulse at your wrist, but that doesn't make me anything special. So can a few million nurses, doctors and paramedics -- and you can too once you get used to feeling it.

I obviously don't know how Kardia's algorithm actually works, but from using it for 5+ years it was clear to me that any rhythm that was regularly irregular or tachycardic would get tagged as "unclassified." If it was irregularly irregular, it would get classified as "possible afib."

I don't know if the original Kardia looks at anything other than regularity (the "stuff in between"), but I doubt it because it was unable to see all the "stuff in between" very well. Maybe it does with the new 6-lead version, but I don't know for sure. Good question and something I need to look into.

Thanks to both of you! Very insightful posts.

I have a Kardia 6L, but it can do either 1 or 6 lead readings. Yeah sometimes it jumps all over the place (especially the "stuff in between", seemingly randomly. It seems sensitive. But, then I'll read it again and it's fine. I think this even happens with regular EKG machines.

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Carey
and you can too once you get used to feeling it.

Yep, from early on I could diagnose myself in 4 or 5 beats in the radial pulse.

I was at a party and a friend mentioned he had afib. I asked if he was in it now. He said no. I asked if I could feel his pulse. Sure enough he was in afib right then and most likely persistent. Similar things have happened fairly frequently.

How then is greater heart rate variability a good thing in a normal person?

When I look at my EKGs I was thinking it was the absence of a clearly defined p wave that made an irregular rhythm afib.

Lastly, if the above statement is true is there something of a lesser form of AF but still AF? The reason I ask is that I see a slightly developed p-wave and at those times I am feeling better but my device still reports irregular.

I can't make any sense out of these other that when I am out of AF I see a p wave, beats are still irregular and the rate is usually reported as 10-15 less but while taking an AF EKG I see HR bounce all over the place as it reads shorter and longer r to r intervals. As low as 40 and as high as 120. 2 recent readings in photo.

[flic.kr]

(I admit I don't know crap about this but am trying to learn)

Should I buy a Kardia, heading to Texas next month?

I would buy one. They like weekly readings after your ablation.

NotLying, I think you're overthinking things. Forget R waves and P waves for a minute. Feel your pulse. If you can't predict when the next beat will happen, it's probably AF. Simple as that.

Driver, yes. For the reason that Cirene mentioned and also for your own piece of mind in the coming months.

As Carey wrote, when you're used to do it, you can feel afib just checking pulses with your fingertip for some seconds.
I use my EKG device from time to time just to keep some tracings to show my doctors.

There are cheap small devices like this one that, funnily, are more acurate (mine is) measuring HR than measurinh %SpO2. The small tracing one can select to be shown on the display has nothing to see with EKG tracings, but it clearly shows the regularity of R-R intervals. This device does the same thing as my finger checking my pulses, and the displayed average rate is accurate.

My omron bp meter will report irregularities and I have a couple of dedicated devices that do EKGs or ECGs (what ever is the right term)

I am now wondering if those with higher HRV are actually endurance athletes headed toward AF.

In 1987, the very first time I put on a wireless HRM it was at the OTC sports physiology lab in Colorado Springs and after walking up to the 2nd floor (at altitude) they initially thought the device was defective as it reported 27 bpm.

Criminal that these $9 spO2 meters are now priced at $69 - it's not a good covid detection (nor is temp) because lowered spO2 is late stage. (fever only in 31% of confirmed covid admitted into hospital) so may be as low as a few percent.

This is a nasty virus.

So, if your RR interval is regular is that the primary gauge on how good you're doing during the blanking period? Or, is having 2 perfect humps in between just as important? Or, in a normal rhythm is having some variation "in between" common?

Just a curiosity.

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cirenepurzalot
So, if your RR interval is regular is that the primary gauge on how good you're doing during the blanking period? Or, is having 2 perfect humps in between just as important? Or, in a normal rhythm is having some variation "in between" common?

Just a curiosity.

A normal heart has variation. It is relatively small by comparison to the variability of afib, which is huge. Heart rate variability is actually considered healthy. It is generally larger in the young and the fit than the old and sedentary.

This is an example of my heart rate during a 10 minute segment of sleep.

Heart rate image

You can see that beats that have a large variation to the next beat, that variation is maybe a couple of BPM. In afib, this could easily be 60 or 70 BPM, beat to beat.

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cirenepurzalot
So, if your RR interval is regular is that the primary gauge on how good you're doing during the blanking period? Or, is having 2 perfect humps in between just as important? Or, in a normal rhythm is having some variation "in between" common?

The primary gauge of how well you're doing is simply not experiencing any tachy-arrhythmias. There's not much to be gleaned about your progress from a normal ECG.