If I were you, I wouldn't rely to much on this one reading. Several things can affect your bp... in fact just walking around walmart for a little while can elevate it somewhat and I'm not sure how accurate those drug store machines are anyway. Personally... I hate Walmart with a passion, so I know just being there would cause my bp to go up!
I'd get one or two more readings just to be sure. In any event, for high BP, it's good to limit salt, eat a healthy diet and exercise... just like every other ailment!
Also, 260mg of sodium is not the daily limit!! The RDA for sodium is 2.3g or 2300 mg, so the salsa isn't the bad guy! In fact, it's usually a very health snack option, so keep it up!
Good Health to you!