Hi Tracey, breathing problems come and go but are so bad now they are saying I can't have my final chemo which is due next Tuesday. Don't know about the Herceptin yet. They want to repeat heart tests and have me see a cardiologist. I am reading the same thing as you about many other women having the same side effect on Docetaxel! Why don't they acknowledge this???? Makes me so frustrated because I DON'T want them to stop me from having the next chemo as I know I will worry about the cancer coming back. I had my worst attack of breathlessness yesterday. I was hypotensive with really low blood pressure for about an hour during the attack. I know my dr had said to go to hospital if it happened again but she already calls me 'complicated' and 'a frequent flyer' which makes me feel like a drama queen and then when they don't find anything seriously wrong with me at hospital, it makes me even more reluctant to ever go back. It means a lot that you and Linda remind me that I will get through this because it certainly doesn't feel that way at the moment when i can barely get out of bed.