Thanks for your question on Healthcare Magic.
I can understand your concern.
In my opinion, she might be having metastases in the heart muscles (myocardium).
This can cause poor functioning of heart muscles and so pumping is reduced.
Angiography will detect if there is blockage in coronary arteries. Since her angiography is normal, her coronary arteries are clear from blockage.
So her poor heart pumping is mostly due to myocardium involvement.
This will cause retention of fluid in the body organs like lungs, abdomen, lower limb etc.
So get done PFT scan for the diagnosis of myocardium involvement.
And yes, this is not good sign for prognosis.
If you wish, you can ask me directly on bit.ly/askdrkaushalbhavsar with allergies the reports.
Hope I have solved your query. I will be happy to help you further. Wishing good health to your mother. Thanks.