https://www.cnet.com/news/apple-watch-series-4-ekg-heart-rate-monitor-next-level/

Four years and five versions since its September 2014 unveiling, the Apple Watch isn't just among the best-selling smartwatches, it's said to be the top-selling watch brand, period. And for 2018, the company is leaning in to that success with its first big redesign to date. The Series 4 boasts a thinner body, a bigger screen, a faster processor and -- on the high-end model -- a stronger LTE signal, so you can leave the iPhone at home on those early-morning runs.

But the price tag of new models has edged up, too, with the new model starting at $400. So how is Apple enticing existing users to upgrade -- and new users to take the first-time plunge? Simple: It's making the Apple Watch a must-have health companion with a first-ever built-in electrocardiogram (EKG or ECG).