Cancer treatments can sometimes lead to some cardiomyopathy but I believe after the treatments are over, the heart will recover. There are some wonderful meds to help improve the ejection fraction and help her to feel better.
Another suggestion is to post your thoughts on the "heart disease" forum and ask about chemo triggered heart disease.
I noticed in the forum that they have a cancer forum right next to caregiver, did you mean to post this in the caregiver or cancer forum? you will probably get more answere in cancer forum few people go to this colum for some reason luck jo
I wish that i could give you some advice on the meds, but i do not know enough about that I do know about cancer, my husband had it his was cancer of bladder, it is now in remssion, but then he had a stroke, and is a shut in we are older people, All i can give you is Hope, Give your wife all the love you can, yes the Dr should inform you on all medications. there is no one hundred percent cure for cancer, my daughter has cancer of the throat, and took radiation, she has to drink liquids, but she is alive, she lives to far away to visit often, but we stay in touch and call, and i pray every night for her to survive, I am so sorry for the little ones, and i feel for both you and your wife, Try to Pray, and find some peace, i wish i could set your mind at rest, but please do not think you are alone, try to find the outreach for cancer patients and family, they may be able to help you through these trying times God bless all of you jo