Samsung’s official announcement suggests that you need a separate blood pressure cuff to calibrate the watch, suggesting you need to recalibrate every four weeks. It looks like you need a cuff-design blood pressure monitor to maintain accurate readings. We certainly don’t have one hanging around, and Samsung doesn’t say if it’s selling one.

Sammobile said that the updated app is rolling out now and new firmware for the Watch should be available to download for Korean owners. It’s unclear if and when ECG and blood pressure monitoring will come to the watch in other countries.