AliveCor’s Kardia Mobile ECG Accurately Identifies Atrial Fibrillation >120 BPM

The skeptical cardiologist revealed recently that the  Apple Watch (AW) ECG app is incapable of identifying atrial fibrillation (AF) if the heart rate is greater than 120 beats per minute. It labels these recordings as “inconclusive”.

Since it is common for AF to present at rates >120 BPM, AW ECG will fail to notify many (if not most) of its users that they are in AF.

AliveCor’s Kardia mobile ECG device (both the single lead and the six lead), on the other hand, has no problems identifying AF >120 BPM. I have found that the Kardia ECG was highly accurate in patients with rapid AF from using the device in hundreds of my patients since 2013.

After writing about the AW AF flaw I opened my KardiaPro dashboard which connects to the online ECG recordings each of my patients has made.

Two of my patients with paroxysmal AF had gone into AF in the last 2  days and made recordings.

Both of them had rates > 120 BPM. In both cases, Kardia had easily made the diagnosis. AW would have declared these “inconclusive.”

Patients should be aware of this AW AF flaw. The absence of a declaration of possible AF on the AW ECG should not reassure anyone of the absence of AF.

AW users should have their high rate recordings reviewed by a cardiologist.

Alternatively, they could purchase a Kardia device and utilize it for heart rates over 120 BPM.

Tachyagnostically Yours,



2 thoughts on “AliveCor’s Kardia Mobile ECG Accurately Identifies Atrial Fibrillation >120 BPM”

  1. Apologies – I have just noticed that my questions were superfluous as the article mentioned both single and 6 lead Kardia devices both detected AFIB with HR > 120.

    Thanks again for very interesting articles on important topics that are usually not featured elsewhere.

  2. Thank you for this helpful post.

    I started using the original Kardia device, with two electrodes to place a finger on each, about 4-5 years ago

    I then upgraded the single electrode Kardia band for AW as soon as it was released, which is far more convenient than the original.

    I presume in this report the Kardia band for AW was used?

    Have you found any difference in accuracy between the original two electrode and the Kardia AW band?

    Have you had a chance to test out the new 6 lead Kardia under this set of circumstances?

    I find the greatest use of the AW is the workout app, especially the heart rate recovery at the end of a workout. HR drops from 131 to 99 in two minutes, with a HR drop of 32 a good result.

    The article on AFIB and lifestyle was excellent- since abstaining from a very moderate intake of alcohol the PACs and PVCs have disappeared, so very likely your advice applies to anyone with any electrical irregularities.


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