We answer how it works, how accurate it is and what’s new with the Series 4

Over time, the Apple Watch has grown into quite the everyday heart rate monitor, but things have ramped up considerably with the new Series 4 and watchOS 5.

After dipping into some basic heart health through the previous smartwatch – giving users a high heart rate notification and resting heart rate stats – the Apple Watch Series 4 will now feature medical-grade accuracy through ECG monitoring.
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Reaf full post here:
https://www.wareable.com/apple/apple-watch-heart-rate-monitor-guide-340