Device for Showing Per Beat Heart Rate?

The most useful heart rythm monitoring method I have tried myself is a Polar chest strap combined with the iphone app Elite HRV. I'll give a quick explanation in case anyone reading isn't familiar with the kind of plot it shows. Rather than ploting electrical activity VS time, it shows heart rate VS time (please tell me if you know the proper name for this kind of plot). It's an HRV app, so the point of showing this plot is so that you can see healthy sinus arythmia which show up as waves. But when things are out of whack, like with afib, it's all over the place and you can clearly see this. And ectopics and atrial flutter are very distinct. And you get to see an entire minute of everything that has gone on rather than just a few seconds typical of apps showing rythm strips. It just seems like a more intuitive way to visualize variations in heart beat timing. To me, looking at rythm strips to find irregular heart beats is kind of like looking at your car odometer changing to figure out car speed...

The downside of my setup is that wearing a chest strap kind of sucks. So I'm wondering if anyone knows of more convenient monitoring devices that can show, perhaps via an app, this kind of plot. Mainly, I'm wondering if it can be done with apple watch. I get that it won't be as accurate given the chest strap makes solid reliable electrical contact with the chest, but I still want to consider this option given the convenience of apple watch. Or any other suggestions?

Below are some example plots from Elite HRV in case any one wants to see. The first is normal sinus arrythmia around 5 breaths per minute. The next is while on exercise bike all going well. The third shows an ectopic (not sure if PAC or PVC, maybe one goes up the other down...). The fourth is still exercise bike but something has gone wonky with my heart and I have to reduce intensity till it calms down. I've worn a holter monitor at the exact time this has happened and pressed an event, but the report said it was just high heart rate. It's like this kind of plot is better for highlighting even small electrical disturbances than conventioan rythm charts perhaps. I would be interested to know if anyone has any thoghts on this odd bit of rythm...

Thanks!






For some reason, images aren't showing, so I'll attach in the correct order... I can only attach three so skipping the ectopic one...



Edited 1 time(s). Last edit at 06/27/2023 04:10PM by SamIAm.

Quote
SamIAm
To me, looking at rhythm strips to find irregular heart beats is kind of like looking at your car odometer changing to figure out car speed...

Not going in the way of more convenient, but I've used Polar devices that will record beat to beat or "RR" data for probably 18 1/2 years, starting with the old Polar S810i watch. Around 2014 I migrated, still using a Polar chest strap, to an app, Heart Rate Variability Logger, which is really made for research. You can see my posts on this app here. Polar does make a Bluetooth arm cuff that uses plethysmography to detect heart beat. My daughter and her husband have one and I think it works OK. I just appreciate the data I get from the chest strap.

The real time heart rate display on the app is a moving average, though the RR time in ms is actual data. The app will export the RR data to a .csv file that I put into file that will load into ancient Windows Polar software for display. I've done this for overnight recording and record most of my afib episodes with the app, though I don't go to the trouble of downloading ever episode.

We discussed this back in 2006 here and in 2008 here. One of our members sent me a whole bunch of different rhythms he captured here.

The reason I still use this setup is, while not seeming efficient, I can look at 8 hours worth of data during sleep and quickly see the ectopics or anomalous beats I'm interested in. I generally look at a 20 minute window of data & zoom in as necessary to get more detail, if I need it. In this post, from January 2021, I posted data from a ring that uses plethysmography for both O2 saturation & BPM, recording every 4 seconds and from the Polar data, as I had both on. It shows why you want the beat to beat data, for our purposes. Old school, but works for me & I tutored one of our members in NZ in the last year or so on this and he found it useful as well.

Thanks GeorgeN. Wow, you've been using this a long time, ahead of the game! Did you see that third pic I attached? Have you ever encountered anything like that? It is so odd that it shows up as dramatically different yet nothing was picked up on the holter from the event time... I asked my cardiologist, but he just said it was noise. I explained it happens when I pedal harder and then goes away when I eas off, and he was still convinced it was just noise. Typical...

If you haven't yet, maybe check out elite hrv, it works really great with the polar straps. I too have logged with the heart rate variability logger, and wrote some crude scripts to count PACs. But I'm looking for something as convenient as possible now. The arm band you mention is definitely on the right track. I tried one and it had less noise than wrist methods but more than chest straps... But the convenience of the apple watch and other uses for it make me want to get this way of looking at RR data working on it.

Would be great if someone with Apple watch chimed in. Still interesetd in other ideas too though, thanks all!



Edited 1 time(s). Last edit at 06/27/2023 05:57PM by SamIAm.

I don't know if more convenient, but Wellue makes offers 24/7 ekg monitoring with the option of a disposable patch, similar what you would get from your ep. The advantage here is no slipping and sliding which was my problem when I tried to record using the Polar strap at night. Not sure if it offers all the other features you are looking at, but their website should have that info.

Quote
SamIAm
Thanks GeorgeN. Wow, you've been using this a long time, ahead of the game! Did you see that third pic I attached?

Can you zoom in? I assume that is with the "Open HRV reading" function (which I never use). I use Elite HRV, but not for this purpose, just for a morning HRV. However I'm not all that happy with it for that purpose, because if you have a bad strap connection it won't let you restart the reading. I'd love to have the RR data and be able to zoom in with the Polar software. My guess is they are PAC's. The "slow" beats may be compensatory beats after the PAC. Hence the beat after the PAC ends at (basically) the same time as it would have had there been no PAC.

If you could zoom in, you could also see if it was PAC compensatory PAC compensatory ... or if you had some "normal" beat(s) in between.

Quote

Have you ever encountered anything like that? It is so odd that it shows up as dramatically different yet nothing was picked up on the holter from the event time... I asked my cardiologist, but he just said it was noise. I explained it happens when I pedal harder and then goes away when I eas off, and he was still convinced it was just noise. Typical...

It is possible it is artifact. If you used heart rate monitor or electrode gel on the strap (maybe you already do), you'd have a better shot of not having artifact. If the Holter didn't see the PAC's they very well could be artifact (Holters can get artifact, too).

I've rather than writing scripts, I've found that I learn more examining the data visually.

By the way, the Polar straps don't "see" the malformed QRS of a PVC. Hence the PVC signature is a beat that is about 1/2 the speed of the surrounding beats as the strap is actually reporting the RR time between the beat before and the beat after the PVC (hence BPM is 1/2 and RR time in ms is 2x). I proved this to myself running a home built ECG and a Polar strap simultaneously around 2005. The strap algorithms have not changed since, though the transmission frequencies have. The H10 strap still broadcasts in the old frequencies in addition to Bluetooth and Ant+.

Nineteen years ago, chronic fitness was my path to afib. I empirically determined that for long duration endurance, Zone 2 was not a trigger, but higher zones were. I can do short duration intervals, like 8 reps of 15 seconds as hard as possible, 15 seconds at 50 watts on my fan bike, without issue. You can see my Zone 2 posts here. This thread is a good one on the exercise topic. Basically, my trigger was the product of intensity times duration.

On the artifact topic, one metric I used when I was designing my afib remission program, with detraining to Zone 2 levels (& I didn't know what Z2 was, I was just figuring out what exertion levels were vagal triggers - I learned that my empirical level matched with what is called Z2 much later) & electrolyte supplements 18+ years ago, was PAC and PVC counts while meditating or asleep. I would meditate or sleep reclining on a recliner couch so as not to move and to absolutely minimize artifact.

Thanks mjamesone, I've contacted Wellue to see what it can do.

GeorgeN, thanks for all info, I think I'll read through some of your other posts too. I don't think Elite HRV can zoom in... I'm certain it isn't artifact because it is very repeatable (I just have to pedal harder, my body is still) and I feel the difference in my chest. It happens when I increase intensity too early during exercise, if I ramp up over 20 minutes, then it is much more stable. Just odd that this doesn't come up on holter, they didn't even say I was having PACs at that time (other times they did). I'll try to get an actual rhythm strip for the same time to study. There is an app that produces rhythm strips fromt the polar H10 now, though I haven't tried it yet.

Still hoping someone with Apple Watch can chime in :-)

Quote
SamIAm
I'm certain it isn't artifact because it is very repeatable (I just have to pedal harder, my body is still) and I feel the difference in my chest. It happens when I increase intensity too early during exercise, if I ramp up over 20 minutes, then it is much more stable. Just odd that this doesn't come up on holter, they didn't even say I was having PACs at that time (other times they did). I'll try to get an actual rhythm strip for the same time to study.

Some Holter software can produce a "tachogram", which is what a Polar RR heart rate vs. time graph is called in EP research. You could ask and see if they can provide for that segment of the Holter. Also known as "RR-interval time series." Maybe even give it to you in digital format (.csv?).

Here is one paper where they talked about using these types of data.

I'd previously purchased and looked at the app you linked above. Not very useful IMO. I don't think the author put much time in on developing the app.

The Apple watch records: HRV, Rate, Cardio Recovery, Cardio Fitness, Walking Heart Rate, Resting heart rate, Afib History.

Afib history gives a report once a week as a percentage of time you were in afib in the last week. Obviously the percentage is based on the time you wore the watch. If you open up the others I listed you then can select day, week, month, 6 months, or year. All of the ones listed are in graph format

You can see your BPM. The graph is from midnight to midnight. It will record/display the highest rate and the lowest throughout the day. If rate changes it gets reflected on the graph. I have my watch set up so the heart rate icon is displayed on my home screen. I just touch the heart and it gives current BPM w the graph.

Any EKG taken is saved to your iPhone, unlike Kardia which requires additional monthly charges to maintain your strips on their cloud. Hope this helps.



Edited 3 time(s). Last edit at 06/28/2023 04:52PM by JakeS.

Sorry one more point. When you activate the exercise for example running it activates a timer, records distance, shows your pulse during the workout, your calorie burn. At the end of the exercise it indicates your low and high BPM as well as the average BPM. It also records the current temp and humidity.

JakeS, all that data the apple watch provides sounds extraordinary. The main thing I'm hoping for is the RR-interval chart GeorgeN points out is called a tachogram. Any idea if there is a way to take the watch data and have it displayed on a phone like I've shown in the pictures attached to opening post?

GeorgeN, regarding the "ECG EKG Viewer for Polar H10" app, all I'm hoping to use it for is to create a pdf of a rhythm strip I can send to my cardiologist. Is it at least capable of this? I figure it would be better than using the kardia or apple watch for this purpose as the chest strap has a lot less noise. Though please tell me if the app wouldn't even be good for this...

Thank you all for all the help!



Edited 1 time(s). Last edit at 06/28/2023 06:46PM by SamIAm.

Quote
SamIAm
regarding the "ECG EKG Viewer for Polar H10" app, all I'm hoping to use it for is to create a pdf of a rhythm strip I can send to my cardiologist. Is it at least capable of this? I figure it would be better than using the kardia or apple watch for this purpose as the chest strap has a lot less noise. Though please tell me if the app wouldn't even be good for this...

I assume you will be exercising when you record? Let me know & I'll do something like that so you can see.

You can export the file to .csv



Now I remember playing with it. Because of the ECG, those data are sampled very frequently and you get a lot. As I recall, the heart rate is sampled every second and the HRV time as it occurs, so their fields are commonly blank for most of the ECG samples (because there are so many more).

I would be using it both exercising and not exercising. It only exports a csv file? I was hoping it exported a pdf with rythm strip on proper graph paper my cardiologist would be familiar with... something like kardia or apple watch...

Quote
SamIAm
I would be using it both exercising and not exercising. It only exports a csv file? I was hoping it exported a pdf with rythm strip on proper graph paper my cardiologist would be familiar with... something like kardia or apple watch...

I don't see a way to export PDF.

You can pull up recorded files and display on the screen. You can zoom and pan and take screenshots. For example, here is a 30 second piece of ECG plus RR time (ms), while sitting. The blue is the ECG. Not too useful IMO. You could build your own software to take their .csv and display it how you like.



As an aside, my experience is it is hard to get clean data with a strap while doing RR recordings during training, even with ECG gel. On the Polar site: "Please note that you cannot train with V800 when using the R-R recording feature."
I would think using a plethysmography device would be worse. Source

This data from the strap recorded with Heart Rate Variability Logger, displayed on the old Polar Precision Performance Software. This protocol is a 3 minute warm up at 50 watts on the fan bike, then 8 cycles of 15 seconds as hard as I can go (I'm 68, so heart rates are relatively low) and 15 seconds at 50 watts followed by a 3 minute cooldown. There are a number of what appear to be PAC's & PVC's. However I can't guarantee that the PVC's aren't a dropped beat and the PAC's artifact.

image upload account

Regarding the Apple Watch. I may be wrong but I believe HRV and RR interval measure are the same? If I am wrong hope someone can clarify.

While heart rate focuses on the average beats per minute, heart rate variability (HRV) measures the specific changes in time (or variability) between successive heart beats. The time between beats is measured in milliseconds (ms) and is called an “R-R interval” or “inter-beat interval (IBI).”

The Apple watch does measure HRV.

Quote
JakeS
Regarding the Apple Watch. I may be wrong but I believe HRV and RR interval measure are the same? If I am wrong hope someone can clarify.

While heart rate focuses on the average beats per minute, heart rate variability (HRV) measures the specific changes in time (or variability) between successive heart beats. The time between beats is measured in milliseconds (ms) and is called an “R-R interval” or “inter-beat interval (IBI).”

The Apple watch does measure HRV.

Yes, you are correct, but the point, for our purposes is to be able to see actual beat to beat values (ideally graphed or exported), either as the R-R interval time in ms or that time converted to heart rate in beats per minute. Then you can "see" ectopic beats as well as afib. I believe what is reported on the Apple Watch, as well as many other devices is HRV as a number or perhaps a series of numbers over a period of time. My Oura ring will report overnight HRV as a series from 5 minute "windows" of data.

One of the issues with HRV is if you have afib or ectopics, these values will distort the amplitude of the HRV. Some algorithms try to correct for this, though I'm not convinced they do a great job of this.

As per this page, it looks like the apple watch does send out RR data, but elite HRV hasn't put in the effort to be able to read it yet... Maybe there is an alternative to Elite HRV that can...

GeorgeN, regarding "ECG EKG Viewer for Polar H10", there app page shows a rythm strip pic (below). But this can't be exported as pdf?





Edited 1 time(s). Last edit at 06/29/2023 01:41PM by SamIAm.

Quote
SamIAm
GeorgeN, regarding "ECG EKG Viewer for Polar H10", there app page shows a rhythm strip pic (below). But this can't be exported as pdf?

I see the issue. I have a different app, "ECG EKG Recorder for Polar H10" The one you link may work.

This app is much better. On some of the images, you may have to click on them to get the full vs the truncated image.

I did about 20 minutes on the SkiErg, 15 minutes at my Zone 2/MAF heart rate or less (112 BPM at age 68) standing on the flat side of a Bosu ball behind the machine. See here for example video. Then did 5 minutes in Zone 3.

The app recorded 32 pages, this is page one:


this is page 31 or next to last (if you want the full PDF, PM me your email address):


This is what was recorded by the Erg's computer. Red is heart rate, click to get full image.


I could simultaneously record on the Heart Rate Variability Logger app we discussed above. Here is the output:

Thanks GeorgeN, that is what I am after, I think that is the best thing to send to my cardiologist, much less noisy than apple watch or kardia and can send important snap shot pdf of troublesome time rather than a time I happened to do an ecg. This is the next best thing to a holter I think.

I still might get an apple watch as it is way more conventient and so could give a better idea of how much time I'm spending in afib, even if it can't give a good tachogram or extended period of rhythm chart.

Thank you for all the effort you put into helping me. I'm also inspired by how long you have managed with afib and how you take it so seriously upon yourself to manage it.