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.