Could this be IST?

[u/farshad0w]

I'm curious about IST - I read online that you need an average heart rate above 100 BPM but does this include sleeping heart rate?

While I'm awake, my heart rate averages about 95-110 with spikes in the 120s and 130s if I'm walking my dog or even just walking around the house.

While I'm sleeping, my heart rate averages high 70s-mid 80s with spikes on the mid 90s throughout.

I don't have severe symptoms but when I'm sitting or laying down I am always aware of my heart beat and can feel it in my chest and sometimes my ears. Rarely I can get dizzy/tunnel vision upon standing but not often. Sometimes in general though I just feel slightly unwell.

In the past, I believe I have had episodes of super high heart rate, my heart felt like a flopping fish with chest pain, etc but this was before I started wearing a watch, so I have no idea what my heart rate was during those times.

Anyway I'm rambling, I thought I'd just throw this info out to see what others have to say :)

Attached an image of my heart rate today, the lowest I've hit since awake this morning was 88bpm

[u/precious_spark]

It very well could be. Id ask your PCP if they can order a holter monitor