Smart watch with ECG

You seek an accurate ECG.
Unfortunately no single lead device is ever going to be considered 'accurate' as it's too basic to be considered diagnostic, and is so easily affected by artefact interference that it's very easy to end up with an unreadable recording - Both to the rudimentary AI interpretation system, but often to humans too.

The Kardia 6L Device is about as good as you will get for taking ECGs on the go, but this isn't a smartwatch. And even that still very much has it's flaws. Depending upon what you're hoping to achieve with such a device it may still not be accepted by some doctors, if you're hoping to capture something to show to them.

With the above in mind, if you still want to go ahead then the Apple Watch is the best for ECGs which does mean you need an iPhone. The Samsung Galaxy watches have always struggled to pick up a clean recording in my experience, and you must have a modern Samsung phone for it to work (not just any Android). The Fitbit devices like the Charge and Sense series, and the Pixel Watch family are slightly better but still won't give you a rhythm strip as clean as an Apple Watch can in my experience.

If you don't have a specific reason for needing a smartwatch with ECG Functionality, I would say to just not bother really. If you don't need it, it's going to push the cost up to buy one vs another model that lacks this feature that you'll probably never use anyways. In which case I would recommend the Huawei/Honor bands for the fantastic range of features (but no ECG) and long battery life at a very low cost.

Just thought I would add to this by posting 3 ECGs taken about a minute apart from each other, 3 different devices. First was the Apple Watch, Second was the KardiaMobile, Third was the Fitbit Charge.

(Boring normal sinus rhythm right now, no fancy rhythms to show off today!)

Hopefully this helps show a decent idea of what these will record in ideal conditions when I am relaxed, sitting down resting against a solid table with the a good, snug fit on the watches with perfectly clean hands and electrode contacts.

The problem is that this is all in best case scenarios. If trying to capture something while out and about or active you won't be in best case scenarios. Nor will a single lead recording be enough for a cardiologist to be sure of what they're looking at so you'd be given a holter monitor/event recorder/implanted loop recorder to capture it on a certified and calibrated medical device with more leads - Something they could do anyways without wasting your money on these frankly useless devices.






(edited)