High heart rate and low blood pressure followed a pretty bad case of anemia after my sixth (of six) treatments with taxol and carbo. I started noticing after my third treatment that I had some issues with heart rate and anemia, but my oncologist didn't treat this. Two months after my sixth treatment (in April) I finally convinced my primary care doctor that this was really impeding my recovery. My heart started to race and I would feel dizzy if I did almost anything for more than a couple minutes. I think it helped that I got an inexpensive heart rate monitor at Target and started to track what was happening with my heart rate. It helped me convince my doctor that I wasn't just whining about general fatigue. She treated the heart rate with atenol and the bp with midodrine and it has seemed to help. I think it is very hard for people -- even doctors --- to understand how debilitating this situation is. Good luck to you and hang in there, my friend.
Make sure you discuss any side effects with your doctor, but are you getting steroids with your treatments? I would assume yes as this is common with most chemo, and boy did my chest bound like crazy and my heart raced. Best wishes to you.