Apple Watch gets serious heart monitoring with the new Kardia wrist strap - CNET

Wearable manufacturers talk a big game about "health" and "fitness", but a new accessory for the Apple Watch is looking to up the stakes significantly with a medical grade electrocardiogram (ECG).

AliveCor already makes an FDA-approved ECG accessory for your phone, and the company is now bringing its technology to the Apple Watch.

Kardia Band is pretty much what it sounds like: a strap for the Apple Watch. The magic, though, is the medical-grade ECG built into it. The Kardia Band can also record your heart rate using an integrated sensor, while most current wearables with a heart rate monitor use an LED to track what your heart is up to.

The LED light of these wearables illuminates your capillaries and then measures the frequency of your blood flow. As CNET's Sharon Profis discovered some time ago, it can be a decent indication of resting heart rate, but it's often not particularly good when your heart rate is elevated.

And that's where the Kardia Band comes in. It not only monitors your heart rate, but it directly communicates with the Kardia app, which runs the data through an analysis algorithm to detect the presence of atrial defibrillation. That's basically a fancy term for a wildly irregular heartbeat and it's a common cause of stroke.