I have suffered from Tachycardia in the last couple of years and the Cardiologist I saw said for avoid the medication route (beta blockers) to solve the problem, due it lobbing a chunk off Max HR.
My HR doesn’t get high at the best of times, so i took no convincing.
I’ve actually got the Tachycardia under control by easing back a bit on my training. MV plans rather than HV for example. A little less has been more!