HI to both. I have sinus tachycardia and have had for years.  The problem
with taking a beta blocker is that unless you take it all the time it
won't help.  Sine most episodes don't last all that long, if you take it
only when you have an attack, the attack will have passed by the time it
takes effect. If the attacks are frequent or really frightening then it
may pay to take it all the time. At the moment I don't take but I have in
the past and may again in the future.