I am 10 months out of chemo and radiation treatments for triple negative breast cancer. My cardiologist says his echo gram indicates a slight stiffened heart muscle. I had a small amount of fluid around the heart a month ago and am taking a fluid pill. Question: Why when I bend over to work my breath gets shallow and my voice almost goes away and I get light headed and confused. However, 5 minutes of sitting down and I am fine other than a little time. I go back to whatever I was doing and I will have a reoccurrence but can rest again and go back to work. By the time I finish though I am very tired. Can you give me some input on this?