my pulse is very high, can be up to 124. When I stand up, my bp drops a lot. I get dizzy, tightness in the chest and feel ill. I am seeing a cardiologist, my stress test wasn't good, I couldn't complete it. my bp dropped very low when I was on the treadmill, I got off sat down and shot up. I am waiting for 24hr urine results and ct of the head. Have any clue what's going on? I am very weak and out of breath going up stairs?