Using Charge 4 for AFIB

[Gabbee]

I've recently had surgery resulting in AFIB (AF or atrial fibrillation). One of the reasons I bought the Fitbit was to detect and record the periods of AFIB, so that the doctors can consequently adjust my anti-AF meds.

I can do this more or less manually on the basis of pulse and oxygenation (detected by breathing problems), but was assuming that the Fitbit should be able to detect this fairly easily and give me a suitable record.

Any idea how I can do this?

Moderator edit: updated subject for clarity. 

[LZeeW]

@Gabbee   I'm sorry, but the Charge 4 doesn't have the ability to monitor atrial fibrillation.  The only Fitbit that can take an ECG is the Fitbit Sense.  You don't say where you are located, but there is more information you need to know.  The ECG feature is medically regulated, so it isn't available in every country.

[Gabbee]

I'm in Adelaide, Australia.

I'm not sure a 1-lead ECG can detect AF definitively, and wouldn't get the Sense on that basis. Actually I don't think a 5-lead ECG can prove AF - you really need the full 12, to distinguish it from other forms of arrhythmia.

In any case, I would have expected the Charge4 to identify and report irregular heartbeat, based on the varying strength and frequency of the pulse readings over a minute or so.

[LZeeW]

@Gabbee   There are three smartwatches in the US that have an ECG app that are FDA approved for a heart rhythm assessment.  All rely on a single lead ECG for measurement.   I am most familiar with the Sense.  My husband monitors his paroxysmal AF.  He is in AF some of the time, but not all of the time.  The app only gives one of three results.  They are normal sinus rhythm, atrial fibrillation, or inconclusive.  It does not diagnose other rhythms.  These devices are intended for home use and all say that they are not for medical diagnosis and that you should seek care if you are concerned.  My husband's cardiologist, who specializes in heart electrophysiology, was skeptical of the Sense ECG until he saw the recordings.  It changed his mind.

Fitness trackers use PPE (photoplethysmography) to detect heat rate.  There is no FDA approved way of evaluating heart rhythm using PPE.

According to this Fitbit page, the ECG app isn't available in Australia.

[AlanLyttonJones]

I would have thought the Charge-4 would detect irregular heartbeat because my Charge-3 detected my irregular heartbeat in June 2020. I found out by getting an email from Fitbit inviting me to join a study which I did. The study had me wear a Holter Monitor for a week which showed their physician and my physician that I had A-Fib.

[Gabbee]

I guess there are some ways AF can be suspected using the Charge 3/4 at least provisionally, using all the information the fitbit has. I certainly wouldn't bank on this though, or trust that I'd get an email (of some value) from Fitbit.

As someone who has had AF (for a few weeks), I could probably tell when I'm in AF by the raised pulse and breathlessness which occurs with even minimal exercise, but I was looking for something more definitive. Which is why I bought a Charge 5 which (now) has an ECG function in Australia.

But a few days ago I had a false positive from the Charge5. This was followed immediately by 2 sinus readings, and when I looked at the ECG it seemed clear (to me) that I hadn't been in AF, just that the pulse was weak compared to the surrounding 'noise'.

I guess the moral of the story is if I want a more definitive indication of AF I should get a more dedicated monitor than a smart watch.

[AlanLyttonJones]

Right. I would never trust waiting for an email from Fitbit. The reason I got the email from Fitbit was that they were doing a test on some new algorithms and invited me to join the study.

When I go to the dashboard on my phone or on my computer, I don't see any information whether or not that I have an irregular heartbeat although I clearly do which I can determine by taking my pulse. Also, my blood Pressure monitor detects my irregular heartbeat -- sometimes. I have no symptoms of my AF. The only reason that know I have AF is from an EKG.

I am sorry to hear about your symptoms which are brought on by minimal exercise.

[Gabbee]

A couple of days ago I had a false positive Atrial Fibrillation result followed immediately by 2 sinus results. To my untrained eye the ECG didn't look like AF, just relatively weak pulse peaks slightly above the noise. (I would have posted the ECG here but apparently we can't do attachments.)

I knew I didn't have AF because my pulse wasn't raised and there were no other symptoms.

[EarthlyT]

I just read an article that says this feature will work on Fitbit charge 4. Is this not accurate because I just purchased the premium for this reason. 

[Gabbee]

Sorry but no. Charge4 doesn't have ecg, Charge5 does (in some countries).

[LZeeW]

@EarthlyT   @Gabbee   Fitbit is currently rolling out a new feature, the Irregular Rhythm Notifications.  It is different from an ECG.  The ECG is available on the Sense and Charge 5 (in select countries) because it has the hardware to record a 30 second Lead I ECG.  The Irregular Rhythm Notifications (US only) uses the green LED heart rate monitor to look for signs of an irregular rhythm.  It is coming to nine Fitbit models, including the Charge 4.

@EarthlyT   You don't need Premium for this feature.  It is still rolling out, because I know three people who haven't received it.  

[AlanLyttonJones]

I have had a Charge 3 for a few years. Two years ago, I received an email from Fitbit telling me that they had detected an irregular heartbeat. This was a few days after I began noticing my irregular heartbeat. (I was a runner for many years and had a habit of measuring my pulse.) The Fitbit email asked if I wanted to participate in a test they were doing on Fitbit's ability to detect irregular heartbeat. I agreed. They mailed me a heart monitor which I wore for a week and then mailed back to them. They then set up a few telehealth appointments with doctors who asked me questions about my health. It was suggested I contact my PCP which I did. I was able to provide him the ECGs that the monitor had recorded. He had his technician record my ECG. It showed I had A-Fib. He then transferred me to a cardiologist who did her own ECG. She told me that, even though I was asymptomatic at the moment, some day I would need a pacemaker. I'll fast-forward to April 12, 2022 when a Medtronic Micra pacemaker was implanted in the wall of my right Ventricle. Its job is to keep my ppulse above 70 which it does very well. When I'm walking at a moderate rate, my pulse can go to 110 but it never goes below 70 anymore. The battery is supposed to last about 12 years.

Alan

[Gabbee]

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@LZeeW wrote: Fitbit is currently rolling out a new feature, the Irregular Rhythm Notifications.  It is different from an ECG.  The ECG

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Interesting, I guess it will eventually come here.

Does it rely on regular ECG tests or does it run independently?

[JohnHG]

You can absolutely detect a fib with one lead. I have never had to use 12 leads. In fact, you can use zero leads - a stethoscope can detect an irregularly irregular rhythm, which automatically implies persistent a fib. An ECG can then confirm, using a rhythm strip,  which is always one lead.