My breathing problem is isolated to the trachia and occurs when I try to talk or sing. It started about the same time as I started taking mrtoprolol for my atrial fibrillation. I take the lowest level possible so don't know if I should reduce the dosage to see if it affects my cough. I have been taking the medicine for 2 years and the cough has been constant for the last 4 months (although I've had it sporadically over the 2 years). My chest is clear and breathing tests show a higher than norm lung capacity. Most recently I have started wheezing at night and have a tightness in my chest. I also have a mild case of Raynaud's disease (tingling in my finger tips) and read I shouldn't take this medication if I have that disease. What should I do next?