[INDENT]Hi Jackie :) Sorry to hear about your Mother. I have heart disease, and take a medicine similar to this. I am not a doc, so take my advice with a grain of salt please.[/INDENT][INDENT]Since she has taken this med for 5 years without SOB, I doubt this is the problem, although it could be. I will list some of the side affects from this med below, and SOB is one.[/INDENT][INDENT]Coronary artery disease (CAD), is where the arteries that supply the heart muscle become occluded (blocked). This leads to angina (chest pain), and SOB. (toprol should not cause angina at all) Most importantly, these symptoms (angina with SOB) can lead to a heart attack and/or stroke.[/INDENT][INDENT]An echocardiogram can be a valuable diagnostic tool for evaluating the function of the heart, but it cannot see blocked coronary arteries. Stress test are good sometimes in screening for CAD, but these test are notorious for giving false positives and false negatives. Many have had these test showing they were fine and a week or so later, they suffered a heart attack. On the other hand, many have had these test which showed that they had CAD. Subsequently, they were scheduled for the gold standard test, for diagnosing CAD, which is cardiac catheterization, and invasive procedure that has risk of death associated with it, and were found to have no CAD. Cardiologist are hesitant to perform these test on the elderly, unless after having a stress test, the patient continues to have SOB and angina, a clear sign of CAD, and possible impending heart attack. You didn't mention your Mother's age, but she may need you to be her spokesperson in asking these questions to her doctor.[/INDENT][INDENT]Here are the side affects on Toprol, that I copied from the rxlist website: Central Nervous System: Tiredness and dizziness have occurred in about 10 of 100 patients. Depression has been reported in about 5 of 100 patients. Mental confusion and short-term memory loss have been reported. Headache, somnolence, nightmares, and insomnia have also been reported.

Cardiovascular: Shortness of breath and bradycardia have occurred in approximately 3 of 100 patients. Cold extremities; arterial insufficiency, usually of the Raynaud type; palpitations; congestive heart failure; peripheral edema; syncope; chest pain; and hypotension have been reported in about 1 of 100 patients (see CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS).

Respiratory: Wheezing (bronchospasm) and dyspnea have been reported in about 1 of 100 patients (see WARNINGS).[/INDENT]