Hello Joy,
yes being in the medical field is hard for you, guess you have seen it all. You are fortunate to have your family for support and for them to be in jobs that benefit you.
For some having a mastectomy seems to be the only choice (and in some cases it is), but it is not.
I hope your cardiologist gets back to you asap so you can get on with your treatment plan. Remember the squeaky wheel gets all the oil.
My experience from radiation was that the rays are directed across your chest and not into, thus having no effect on the heart or heart muscles. I am sure your team will be able to advise of your particular case.
All the best wishes
Viv