inconclusive

[HGainly]

Hello. I thought I was about to buy a Sense 2 rather than  the Klarna Afib sensor, as I also run - now I'm not so sure. I can't find technical details to compare the sensor in the watch but both the watch and the Klarna ECG sensor both seem to be FDA and CE validated so that's probably OK. Yes?

My main point ..... I am a runner like MANY people who use fitbit. I have a low pulse rate, because I run long (-ish) distances and have done for 35 years  - around 43bpm. As an oldie, I am being told to look out for Afib as my heart is showing occasional ectopic heart beats, though so far no real problem. It seems amongst all the warnings  and cautions in the fitbit AFib description pages, they say that results will be Inconclusive  as I have a heart rate less than 50. What? 😮 Here is a fitness device, and here is a fit runner who needs to monitor his heart, ECG-wise. And I can't?  Really?  I hope it's only caution and not a technological limitation otherwise the fitbit Sense 2 is NOT a good device for fitness, at least mine. Thanks, all information received with gratitude. Jeff.

[NanaRuns]

Please read this article from Harvard Health  about personal ECG measurements.  I think you mean Kardia, not Klarna.  Personal ECG measurement is overhyped and over advertised.  Sounds like you might not need a Kardia either, unless you are getting this advice from your health care professional. And if you’re a serious runner, then do you homework and compare best runner’s watches.

[HGainly]

Hi Nanaruns - yes, I've read similar articles, thanks for the pointer. They admit a possible benefit if you have evidence of irregular heartbeat or possible atrial fibillation which is the case for me. The consultant I visited even went as far as to show me the Kardia (yes, not Klarna, thanks) sensors online, maybe on an Am*z*n list, but didn't spend much time telling me what I should do with it. As the article implies, where are the staff who will analyse these unrequested ECGs? I think the use may become clearer the more significant your heart problems are, which for me is not yet. One thing he did say when I asked if I should stop stressing my heart with runs and pressups, he said "absolutely not!" as did the Dr. who referred me.

But my question is for fitbit. Does the ECG app work reliably, or at all...for those of us whose heartbeats are below 50? If it is not technically possible, this leaves the Sense 2 as a simple boutique fitness monitor with a potential market loss of all long distance runners whose pulses beat slower than 50. i.e. loads of them.

I have done my homework thanks - most runner's watches are too expensive and have irrelevant facilities to justify the price. I don't want to live that much. The ability to tell the time in Seoul 50m underwater isn't a sell to me, but being able to connect to Android is. I run 3 to 4 times a week, have done over 100 'races' over 37 years and intend to go on until I can't. That might not be serious to you, I don't know. There's always someone whose heels are in front of yours. This sadly gets worse the older you get and suddenly age qualified times become more interesting.

Thanks

Jeff.

[LZeeW]

@HGainly   Both Fitbit and the basic Kardia run a 30 second Lead I ECG.  It's a 30 second snapshot in time.  Both devices use proprietary algorithms to analyze the ECG.  You can forward a Fitbit ECG to your doctor.  It looks like Kardia provides a Clinician Review, but it isn't free.

I have a Sense 2.  Full disclaimer: this was given to me by Google.  I'm like you, but my RHR isn't as low as yours, usually 46-48.  The ECG will read Inconclusive - Low Heart Rate.  If you have been advised to use home monitoring to record an ECG, then the Sense 2 won't meet your needs.

The Versa 4 has the same operating system as the Sense 2.  It doesn't have the ECG or EDA hardware.  It might be a better fit for you're still interested in buying a Fitbit, especially when comparing prices.  One thing I want to point out is that all current Fitbits offer a feature called Irregular Rhythm Notifications.  The ECG uses hardware, but the Irregular Rhythm Notification uses the optical heart rate monitor to analyze your background heart rate.  It looks for signs of an irregular rhythm over time.  I was part of the Fitbit Heart Study that collected the data for this feature.  A low RHR isn't a limitation or I would have been excluded.

[HGainly]

Hi LZeeW - thanks for reply. 'Proprietary' means that Kardia's algorithm won't necessarily have that limitation I guess?

When you say the Sense 2 ECG is classified as Inconclusive - does it show the ECG with that warning or does it just not attempt to do it? I'm guessing the latter. On the basis that a heart can beat arhythmically at any time, I guess doing an ECG after a run, somewhere down the recovery slope when the pulse is > 50 is some sort of solution.

As far as irregular heartbeats is concerned, the ectopic intrusions into my regular heart beat mean that my heartbeat is irregular a lot of the time. A beat here, a beat there, nothing to worry about they say, but enough to provoke a IRN monitor response. I think the exceptions are more informative than the rule.

The other problem is the continuous heart monitoring which apparently the Sense 2 does. Is that electrical, and therefore subject to min. bpm of 50 or is it optical which I presume doesn't have that limitation?

I don't particularly need to buy a fitbit as I use a phone for routes, simple times etc. There just suddenly seemed to be a good time to cross over - now, not so much. Maybe the other monitors could be useful. Trouble is, I found chest belts difficult to deal with (i.e. keep on) though I could use my Wahoo belt with a paid version of Map My Run or Strava I'm guessing.

Thanks again.

[LZeeW · Accepted solution]

@HGainly  Proprietary means that it's an algorithm that Fitbit developed and owns.  Think protection from patent infringement.  Here is a screenshot of an ECG typical result for me:

App screenshot

As you can see, you can download/save and export a PDF of the ECG trace.  This site doesn't support PDF, so I can't upload an example.

I'm 68 and get occasional PVCs, too.  Sometimes I feel like they are more frequent than other days.  Atrial fibrillation is a sustained irregular rhythm.  I have never received an irregular rhythm notification.  This feature uses the optical heart rate monitor, so it includes all current (and some older model) trackers and smartwatches.  I think I was using a Versa 2 at the time of the study.  There is no low heart rate limitation in the IRN.

I hope this information answers more of your questions.

[HGainly]

---

Atrial fibrillation is a sustained irregular rhythm.  I have never received an irregular rhythm notification. 

I hope this information answers more of your questions.

---

Yes, thanks it does. I read somewhere (a US Med. site) that 'any heart cell' can generate ectopic beats. These interrupt the sinus rhythm which has to adjust and which then gives rise to irregularity. AFib is, as you say, consistent irregularity over a substantial period. I can't see that watch tech is going to be significant unless that happens.

Oddly enough, between these last two posts, a friend of mine, another oldie though not a runner, had to go to a cardiologist with a high degree of hurry up who confirmed Afib. His pulse was very irregular. The significant thing though was his bpm  - it reached about 160. He has now been prescribed drugs which are bringing the rate down. His normal bpm was in the 50s he says. He said he was able to show the cardiologist heart data from his Apple Watch (4) but it was still after the event as additional confirmation rather than data that needed to be sent to a Dr. to say "come in and hurry!"

Anyway, thanks for your help. It did answer my points and I just wish the Sense 2 was more tuned to the people who could benefit most, runners with bradycardia!

Thanks

Jeff.

[t.parker]

@HGainly what @LZeeW said is correct. I would add that the ECG feature came much sooner than irregular rhythm notifications and it's very possible, the algorithms were just trained on different datasets. Hence, the limitation on the ECG doesn't seem to occur on the IRN. Other solutions may or may not have such limitations. I get always "Inconclusive" results on the ECG as my resting HR is between 39bpm-45bpm and when doing nothing it hovers below 50 (with exception of being strained with training, then sometimes it goes up due to fatigue). I'm also a long-distance runner but I wouldn't use Fitbit as a device to tell me any medical-related stuff. It's a toy, not a piece of medical-grade equipment (YMMV). In general, I wouldn't trust any fitness wearable when it comes to diagnosing serious health issues. But that's me.

The AFib is linked with people with low resting HR, however, there is no evidence that athletes are more/less prone to have it. Most of the research groups include a variety of people and usually only a few athletes which couldn't give a satisfying conclusion. There are different reasons why athletes have low RHR and why non-athletic people do so. In my case, it was also one of the suspected possibilities. Long before, I used to be an obese person with low (50 to 60bpm) resting HR so went through a variety of tests to eliminate potential threats to my health (well, I just have interesting genetics - that was a conclusion). Would I use a watch to monitor that? Probably not. Those devices can't handle tracking my running with accuracy, let alone very monitoring potential health risks.

"The ability to tell the time in Seoul 50m underwater" - technically, Sense 2 tells you that, too. 😛 As a runner, I prefer to know things like my cadence, and hike/run ratio (on ultra distances when sometimes there's no other way but hike), I want to know whether I improve or not (comparing my races). When running long new trails (I often run to explore), I need in-watch map navigation. Running dynamics metrics help prevent injuries (for example, ground contact balance can tell you, whether you going a bit too heavy on one of your sides, which may be hardly noticeable yet build up towards an injury). With stamina and power metrics, I can control my performance, and make sure I don't go too hard (it's easy to overdo at the beginning of the run when one feels fresh and strong but the price of that comes later, isn't it? :)). For some runs (mostly for races), I prepare a structured plan (watch guides me through it) based on elevation, distance, and surface changes (I am mostly a trail runner, I don't like roads and I enjoy running on very technical surfaces :D). Not sure how you did your wearables market research, but a majority of such features are being offered by watches cheaper than Sense 2 or at a comparable price. What I'm missing in the Fitbit ecosystem is, in particular, features for runners (and other sports, too as it couldn't be more disappointing when I tried to see how Sense 2 deals with swimming - for me, it just doesn't support swimming; what it does is a joke). Fitbit may be many things but it's not a runner's platform. Fitbit isn't able to tell pace/distance/time giving a single result (in different places like the app or dashboard or even in different places of the app you'll find data being in the disagreement like multiple distances, multiple durations for the same run etc). It can't even tell me lap time, lap pace, or lap distance - basic features of ANY runner's watch. Instead, it tells me AZM, calories, and steps - things which are probably irrelevant for the majority of runners (how does that help me to get better as a runner?). I understand that it may be more important to me as I do compete but believe me, runner's watches do a lot more for runners than just telling "time in Seoul 50m underwater" 🙂

[HGainly]

Hi T.Parker

I don't need a wealth of running stats really so never considered watches like Garmin, Polar etc. The last watch I had for running kept 30 split times if it was pressed, so was good for halfs etc, and that was it!  Since 'technology' I run with my phone so I can track the route and look at some basic stats using an onboard running app. I'm not sure I need anything else. My body is making those decisions really now. I just mix it up according to a schedule.

When Drs. starting recommending some heart monitoring, specifically ECG graphs I thought I might take the plunge and buy a smartwatch which in my mind, ran the heart stuff but also onboard running apps producing a wealth of stats which hopefully might be interesting, particularly if they were real time and generated from my performance in a run.

But, it looks like I can't make use of the ECG app in the Sense2 and from what you say, their running usefulness is limited. Does a Garmin/Polar watch run any health stuff? I confess to not having looked beyond the £600 aspect. I guess I will now, but still am interested in a recommendation.

I wish I could find out technical info a bit more easily. Marketing puffs are pretty but vague, Tech Radar type stuff is better, but not granular enough and technical data offered by manufacturers not inclined to point out inadequacies.

I wonder what watches the Tarahumara use?

Thanks for the reply, very useful.

Jeff.

[Pharmerjam]

I have a Sense 2 and a Kardia Mobile 6L with Kardia Care subscription.

     I find the FDA approved Kardia to be so much better that the ECG from the Sense 2.

     The Kardia should be better for your case in that it should list your result as below instructions and detect 6 abnormal rhythms. 

   "ECG Analysis
After ECG recording is complete, the
ECG is analyzed to determine if it is at
least 30 seconds long, if it is Normal,
Unclassified, possible Atrial Fibrillation,
Tachycardia or Bradycardia or if it is
too noisy to interpret.
Presence of possible Atrial Fibrillation
(AF) in your ECG results may present
only potential findings. If you are
experiencing any symptoms or have
concerns, contact your physician.
Normal results mean your heart
rate is between 50 and 100 beats
per minute, and shape, timing and
duration of each beat is considered
normal.
Bradycardia results mean your
heart rate is between 40 and
50 beats per minute, and shape,
timing and duration of each beat is
considered normal.
Tachycardia results mean your heart
rate is between 100 and 140 beats
per minute, and shape, timing and
duration of each beat is considered
normal.
An Unclassified message means
the tracing is not Normal, possible
AF, Tachycardia or Bradycardia and
interference was not detected. An
example of an Unclassified tracing is
one where tachycardia is observed.
Unreadable ECG results determines
that you didn’t have proper ECG
recording for analysis. You may try
to re-record your ECG.
ECG reports viewed at any magnification other than 100% may
appear distorted 

[HGainly]

Hi Pharmerjam, thanks for reply, great name!

What do you use the Sense 2 for? Are apps, which are not part of the product, resident on the watch or do you have to link to them if they're on something else? IOW if I want to use Map My Run can it be on the watch or does the watch send data to the app on a computer or phone? I can't find answers to these basic questions online, must be missing something.

I can see every time I use the Kardia I will get warnings of Bradycardia. Because of the ectopic beats I suspect I'll get possible Afib too. I can't see what that is telling me as both are 'permanent'. Unless I don't properly understand Afib which as I have just come to it, is very possible. As part of my recent concern, I bought an Omron blood pressure meter - it's always telling me my heart rate is uneven. Almost every time, but my pulse is clumping along between 43 and 48 mostly.

I feel I was recommended (by the Cardiologist) to buy something that will indicate heart irregularity but not go into much detail. Nor do I know what to do with this detail. My friend whose wife detected possible Afib, pesumably after an "I don't feel well" comment just went straight to the hospital and showed them the watch soundings as an afterthought.

What do you get from the Kardia (and Sense 2 I guess) ? Re-assurance or good technical data that COULD be passed on?

Thanks.

Jeff.