Agreed, you rest HR is too high, but not so high as to be an immediate threat I believe.
I believe calcium channel blocker are also used to lower HR, have they been tried?
I have AFib and take a beta blocker to lower my rest HR from around 130 to 80+, so it works. It also lowers my BP, which I didn't need... but different than your problem.
Check out the calcium channel blocker idea. I'm sure your doctor(s) have already considered that treatment.
My resting heart rate is between 115 and 129.... The cardio doc said I am in a constant state of tachardia...... Also I can not take beta blockers per my doc.... I also take 4 medicines for stage 2 hypertension because my blood pressure is out of control diastolically. And they don't know what causing my bp problem............
How high is the HR? It must not be super high (over 130 at rest in my thinking) or I'd think your doctors would seek a cure, even if it required putting you on a pacemaker. I'm not recommending such, just give it as an example of something that might be considered if the HR is "super" high.
If you resting HR is under 100 most of the time, it may not be necessary to treat it. Most, or many, medications used to lower blood pressure also lower HR, but it seems not in your case.
I take Metoprolol (a beta blocker) to lower my HR.