weak heart with herceptin

I have heart failure from contracting a virus back in 2004.  My ejection fraction dropped to 23% before I was diagnosed, and I could have dropped dead, the doctor later told me.  I was put on special medication and now I am generally around 50% and live a normal life except that I get puffed on stairs and hills.  It does add a bit of interest to operations, as I get questioned very closely about it by the surgeon and the anaesthetist every time.  A normal ejection fraction isn't 100%.  It is between 55% and 70%, so you are not as far down as you might think that you are.  Those symptoms are normal for a lowered ejection fraction.  I can't answer your Herceptin question, but be sure that your doctor will monitor your heart closely and not let you drop to dangerous ejection fraction levels.