Inderal LA and SOB

Hi ,

I have been taking Inderal LA 120 since Feb. Started with heart palpatations due to caffeine in Nov. 07.  I am a 52 yr old female.  I never had any problem with racing heart rate until one day in November after drinking a Starbuck Latte.  I went to work out and afterward i came home and I felt my heart pounding up to 130 bpm.  It lasted about 5 min. and then gradually came back down, but after that episode I started having more, all related to drinking coffee.   Anyway, this whole thing has made me a nervous wreck.  I know that doesn't help., but I can't help it/  I am ALWAYS thinking about how fast my heart is beating.  I work out 5 or 6 times a week, but am hesitant to let my heart rate get past 120 for fear it will start racing and won't stop.  Like I said I am on Inderal 120 LA.  My question is this....when I work out now on the elliptical, I feel short of breath.....I don't know if this is because I am worried about my heart rate or maybe from the medicine.  Anyone else have this problem.  Thanks,
Pam