Thank you both so much for responding. It is true that who knows what is causing what or what combination of things can cause what. My mom did have an echocaridogram in early August, along with an EKG - both normal. But if the CT shows nothing new, maybe we'll ask for another. She has really seemed to stump the pulmonologist, but thankfully he hasn't given up on finding a cause yet.
The respiratory therapy doesn't seem to be doing much for my mom either - she is struggling to maintain her weight the way it is. She is such a trooper though and I admire her strength, even more than I did before this horrible disease took hold, if that's possible.
Thank you guys again. You both and Tony have been through so much already and I marvel at your strength as well. I keep you all in my prayers. (((Hugs)))