Hi all, thought you might find this exchange (slightly) helpful.....

Alison Jones, Sep 3, 21:08:

Dear Julia,

Beat Fluctuation (BFx) is a measure of how much your heartbeat changes from beat to beat. BFx varies from person to person and also changes with lifestyle, habits and activities. BFx is represented on a scale from 0 to 100 where lower values indicate less fluctuation. It is an experiment where you may observe how that BFx number changes throughout the day with changes to your lifestyle.

Kind Regards,


Alison Jones, Sep 3, 13:46:

Dear Julia,

Thank you for reaching out to us. I have forwarded your request on to our Product Manager. As soon as I hear back, I will be in touch.

Kind Regards,


Juliatward, Sep 3, 02:59:

Hi, your new BFx feature is no doubt very wonderful but nowhere can I find a simple explanation with examples of what it means. I have asked on the AF forum and no one there can help either. I understand a high BFx is good and low is not but have no idea how to tell which is which. Is there any relationship between the HR and BFx? If my HR is 56 and BFx is 53 for example I have no idea how that is better or worse than a HR of 56 with a BFx of 35. Can the BFx be too high? We need a good explanation in the education section please!

Thank you,


This email is a service from AliveCor Support.


14 Replies

  • How wonderfully American!

  • I'm non the wiser I'm afraid

  • Just more additional waste of information from alivecor. What are we supposed to do with the info in reality. Madly I am getting bfx in the 70's when my bpm are between 58 and 65. what's that supposed to be telling me.

    I had aluvecor saying I was in af when my Ep said no it was lots of ectopics not af at all. So I use it with caution to capture unusual activity when I feel anything. I am with Bobd just use it when needed and dont obsess with it.

    like all gadgets the manufacturers get carried away with their creations but not always the most useful adaptations head our way.

  • I had exactly the same Alivecor said AF - EP said many ectopics, I know who I would go with. However, regardless of Alivecor's take, it did provide an accurate reading to enable EP diagnosis!

  • I assume if my heart beats 70 times a minute - every minute of the day - ie there was no fluctuation whatsoever, my BFx would be zero. Very rare I would think without a pacemaker. As the irregularity becomes more pronounced the BFx rises until, at some point, perhaps at BFx 10 (I'm guessing!), the beat is irregular enough to be called an arrhythmia. A BFx of 100 would indicate maximum chaos within the heart chamber.

    So perhaps we have here a method whereby an individual's AF can be assigned a position on a spectrum enabling someone in persistent AF to see whether or not lifestyle changes can reduce the 'fluctuations', reduce the BFx.

    First time I've ever heard of it but that's how I read it. Though how much use it would be is very uncertain. I suspect the marketing folk at AliveCor are simply looking at increasing the machines features. No doubt it will lift its value in monetary terms if not in functional ones......

  • I believe some variation is the sign of a healthy heart responding to signals from the body such as the vagus nerve, would be interesting to know what it would score as if you had AF?

  • Do they mean heart rate variance? If you google it you will see it is a measurement used in all sorts diagnostic and stress busting techniques,

    It is an incredibly useful no to know as it can be an indicator of stress. I measure mine with a different device and what I notice is that when the variance is high, the electrical activity between HBs is on a different, much higher electrical frequency and doesn't have a smooth curve - that is a biofeedback for me to focus on smoothing it out through breathing and visualisation. Takes practice, but it does work and reduces stress which you can actually see happening, through the HB variance.

    Many athletes also use HRV it to help recovery after exertion. (Step-grandson just won his ticket to Rio by winning European Championships - yeah - Ola Rio)

  • Yes it is heart rate variance but my point was that without some sort of general scale it does not mean much. I think Alivecor is trying to broaden its appeal and compete with other devices which show BFx.

  • What device do you use?

  • Nexus 7 and iPhone 5, android came first but they had trouble with iOS.

  • Buffafly - I had directed that comment to CDreamer but didn't make it clear.

    CDreamer - what device?

  • I use an AliveCor for the ECG but another attachment by HeartMath which is solely for biofeedback meditation and shows only heart variance.

  • There was a mention of BFx in the AFA post about the Alivecor update - but no explanation - just looks like a direct quote from the AliveCor literature. It is not exactly a helpful explanation.

  • Do you remember when the heart was something that did its thing in the background of our lives?

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