The SmartRhythm algorithms look for 2 different things in your heart rate data, each of which triggers one of the two notification types:
- “A possible change in heart rate / activity pattern was detected” occurs when the Watch provided heart rate changed quickly without a change in activity level. For example: Your Apple Watch’s PPG noted a sudden heart rate change from 60BPM to 120BPM but your Apple Watch’s accelerometer did not detect any activity.
- “Heart rate appears inconsistent with the activity level from your watch” occurs when your heart rate is outside of the predicted heart rate band calculated from your activity and heart rate history. For example: Your heart rate is sustained at 140BPM with low or no activity detected by your Watch.