Heart issues???

[fourboysmom]

Help...I am somewhat concerned about my heart function. Had 4 TCH (actually weekly Herceptins), then 4 A/C without Herceptin. I am now every 3 week Herceptins for a year with 2 or 3 remaining. My initial MUGA was high 60's, actually one report said 71 (but I hear that was probably too high). Anyway, one year later I am at 57. That was 2 treatments ago. I don't know if its the heat or what but I gotta rest every couple of minutes, and just don't feel right. I did call my Onc...waiting to hear back.
Should I opt out of the last Herceptin treatments? I feel like I can't win either way...I am 39 and too young to feel weak and short of breath, and can barely keep up with my kids. Thank you for your input, Janet