Can Atenolol 25mg For SVT Safe On A Long Term Use?

I've had SVT most of my life and have lived with it without any real problems, I'm healthy no high blood pressure, not over weight, no thyroid problems, question if this happens 2 times a year, and normally I can stop it myself but when I can't I seek medical help, why would my doctor put me on medication for the rest of my life to control this? Atenolol 25mg, I'm worried that taking these med will effect me in other ways, your thoughts, is it please.