I agree 100% with gmachris518 on the unpredictability of heart failure and about going now and spending time with her.
It's possible the reason the doctor isn't returning your calls is because of the patient privacy laws. To have two-way conversations with the doctor, etc. about your Mom's medical problems, how she's doing, etc., by law, your Mom has to sign a sheet giving the doctor permission to release this information. (Some places even say release of medical information permission forms are good for only 12 months and a new one has to be signed every year. I just found this out at my Mom's doctor's office!) So if you decide to visit, it would be a good idea to get the form signed and in her medical record. Also, I would be sure to list your phone number at the bottom of the form; makes it easier for the nurses, etc. when you call, I found out.
Note that this form is different than a "health care power of attorney form."
Good luck!
At 85 yrs. of age, I would think running out of time to see her would be a given. The swelling, and trouble breathing are definately not good signs, though. A person with CHF can swell, have their lungs fill with fluid and die at anytime. On the other hand, they can go on for quite a long time if the doctor keeps on his toes, but even with the absolute best of care, it's still not a sure thing.
I've had CHF for well over 2 years, with a EF of 15. I've spent time in the hospital on mega doses of lasix, and have had breathing treatments to dry out my lungs. I take huge doses of lasix everyday of my life, and most of the time I feel pretty good, but once in a while the full lungs get me down, and I'm down for the count.
Then there was the fiance' of a friend of mine who had CHF, and while the medical team were standing around trying to decide what they were going to do, she died. Drowning in her own body fluids.
My point.....CHF is highly unpredicatable. If you're worried about not seeing your Mom before she passes, then go to her, spend time with her, because with her ailments you will never know when she will be gone.
My thoughts are with you.