This could be an anxiety response but I've been having heart palpitations this past week. Got blood work yesterday. HCT is 53.1. Am I going to have a heart attack? Do I need to go to urgent care? Incidentally, I do have some big stress going on now.
Your problem is not due to that hematocrit level. I bet you just need to learn how to breathe deeply through your abs when you have anxiety. It really brings heart rate down fast.
Try one or more of these techniques. This really helps me.