Orthostatic hypotension is not related to your heart rate necessarily. It pertains to your blood pressure. With OH, postural change (standing up, or standing for long periods of time) causes your blood pressure to drop. I also had a high average heart rate prior to meds. It stayed around 95-100. I also have episodes of tachycardia without postural change (IST- Inappropriate Sinus Tachycardia), so they are just random. If your heart rate is dropping that low when you are not sleeping (and even then 40 is too low), you might want to work with your cardiologist to see if you are having episodes of bradychardia. That is the opposite of tachycardia, your heart rate drops too low.

No way to edit - hr in the 50s is okay-ish if you are resting but not active.