If you are talking about the Apple watch, that is not true. It's probably fair to say that consumer health tracking devices are controversial, but there is nothing approaching consensus among cardiologists or other relevant experts. You can find articles claiming that devices like this "do more harm than good" (but with remarkably little data to back up that claim) and other articles claiming that they are major lifesavers (also probably an exaggeration).

My cardio team seems perfectly happy to consider data from electronic devices, but of course they want to confirm any such information with more accurate testing, which is exactly what Apple suggests. I just talked to a cardio nurse on the phone, and she spontaneously mentioned that they are identifying many more cases of AFIB these days because of early warnings from devices like Fitbits and Apple Watches. She did NOT say, "Oh yeah, we are overwhelmed with false alarms because of those devices!"

Probably the most ridiculous argument I found in the "more harm than good" camp was the declaration that because most Apple Watch users are young adults they are not highly likely to have AFIB, so it is pointless for Apple to have developed a technology to check for it. As an older adult, I do not appreciate this type of glib generalization.