Pat, it never ceases to amaze me how unique each of us is regarding body chemistry and how it reacts to drugs. I also have mitral valve prolapse and have terrible palpitations. I tried Toprol 25 once/day (1/2 pill so really 12.5 mg) and I was so downed on it I could hardly move. Palps continued to go strong….okay off topic, but the thing is this. I played a wedding (flute and voice — this was before I played harp) and I had absolutely NO anxiety whatsoever. It was as if I were playing at home in my livingroom. Actually it was really nice. That was the only thing I liked about the beta blocker. I had to stop taking them. My blood pressure got so low I could hardly function — and it’s already low. I felt like I had been poisoned when I stopped taking them and realized how bad they make you feel. It reallyb depends on the individual/the drug, etc.