I,m a male 74yrs. old had a three bay pass . Had three test done # 1- 2-D Echo , # 2-Myocardial Perfusion Imaging # -3 COPD test fill all test . they say it could be a blockage in heart . Had a Coronary Angiography done , no blockage. I do two & half mi. on the tread mill in 38 min. at 3.6 speed at 7% incline. IS may heart going bad, no pain in chest , no shortness of breath