Muscle fatigue

[Kd5exp]

I have been having problems for a long time now. After excurting myself for a short time I get a flushed feeling and lose all my strength. My heart Doc put me on a tread mill and I didn't make it 2 minutes. He later induced stress and found nothing wrong with my heart. I have had circulation prpblems and have 4 stints. I figured something was stopped up again. When it happens it's my whole body. I am on blood thinner, 2 blood pressure meds and Tramadol. Went back to my primary Doc and he did blood tests and found nothing that would cause this. Waiting to see a neurologist but can't get in till October. I have had a bad pain in my right bisept for about 2 months now. Can't raise my arm straight out to the side and up. Left arm starting to hurt some now. What could be and could it be serious.