Does anybody know about heart problems with radiation?

Are you considering radiation? What has the radiation oncologist told you? And do you currently have heart issues? If you can add some details I think you'll get some useful response. I gather the heart can be harmed, but that are positions etc. that make it less likely with radiation.

Yes, it definitely can cause problems - I had right side radiation, 40 rounds, because the cancer was in my chest wall post-chemo, where surgery could not cut it out.

I had heart scans before radiation (I was 38) and I do have some lung scarring pist

I have chronic heart disease. I had a bilateral mastectomy in May 2025. Cancer was found in both breasts, early stage. I did not want lumpectomies...because I absolutely did not want radiation which is always done following lumpectomies.
I do not wish to scare you...but, yes, radiation can scar the heart (& lungs) and mimic a heart attack. I was informed of this by my oncology team since I was a heart patient who developed breast cancer.
I already had a damaged heart. So it was very clear to me my option was the best for me.
Of course, you will hear from other women reporting they had no problems at all with radiation affecting their hearts.
No one knows how anything ultimately turns out when comes to cancer, follow up treatments and with existing health issues. It is all individualized. I am simply passing on the heart information I was clearly told in consultations with my breast surgeon. She would have been practicing very poorly if she did NOT tell me all the risks with radiation and the heart (& lungs). I had full trust in her. I don't regret my decision at all.
The very best of luck to you - research this more and you will make an informed decision on which way to go.
Nothing is easy in or with cancer. Nothing. Risks and benefits are always there. Weigh your options - risks vs. benefits. You will make the right choice for yourself. All the best!