Herceptin and heart damage

Has anyone continued with herceptin after having a decrease in ventricular ejection fraction? I have been on docetaxel, carboplatin, and herceptin for stage one invasive ductile carcinoma which is her2 and estrogen receptor positive. The plan was to continue the herceptin for a year but my Echocardiogram is showing some signs of heart damage. Has anyone else had this problem? Please advise! I'm quite short of breath and my heart rate goes up to 120 just walking from the bedroom to the bathroom. Thanks in advance!

Debby Lee