Hello, Had Echo Yesterday With LVEF 50-55%, However It Is

Hello, had echo yesterday with LVEF 50-55%, however it is down 10% from original rate 6 months ago. I am HER2+ breast cancer survivor, ER- PR-, no lymph node involvement. Had 5 TCHP chemo pre-surgery and an additional 2 Herceptin. Scheduled to continue until 04/2017. I am experiencing SHOB, dizziness, and fatigue. Onco is referring me to Cardio. I have an infusion set for next Friday and I am prone to waiting until I see Cardio before another infusion. Any suggestions much appreciated. Thank you, Karen