high heart rate alert: >120 bpm after 10 minutes inactivity OR >120 bpm for 10 minutes

The second one.

Heart health notifications on your Apple Watch – Apple Support

My watch showed a reading of 153 and I had been in bed for hours. My set upper limit for periods of inactivity was 100. I received no notification. I think the 153 rate was of short duration. See photo below. Does the heart rate have to be above the set maximum for some minimum period of time before a notification is triggered? Apple support states,

" If your heart rate remains above or below a chosen beats per minute (BPM) while you appear to have been inactive for a period of 10 minutes, your Apple Watch can notify you. "

What does remains mean in this context?? To me it implies that short periods of elevation above the set maximum will not trigger a notification.

Clearly, I was inactive for a lot more than 10 minutes before my heart rate went over my set maximum of 100, yet I received no notification of an elevated heart rate (153) of short duration. I hope someone can provide an answer....there is no Apple Store anywhere near me. Thanks in advance for your responses.

The watch;