I have controlled high BP for 3 years with Micardis HCT 80/25mg, Amlodipine 2.5mg and Atenolol 50 mg plus on Simvastatin 20 mg for cholesterol. My pulse is low 40's most of time rising to mid 60's with exercise. I have shortness of breath but chest x-ray was clear & pulmonary function test w/ treadmill was ok. I am on BiPap w/1 liter of O2 each night that has raised my O2 levels at night to low to mid 90% (live in 7000' elevation) but pulse continues to be low. I feel the problem causing some of my sleep apnea maybe thyroid which has not been tested. Am I on the right track or could it be something else?