It sounds like mostly vascular TOS with the heaviness & weakness you describe, plus the doppler result.

[a therapist who specializes in TOS. ] is good.
Was the previous PT mainly focused on the CT & shoulder rehab sx??

If working, therapy results will take a lot longer due to the accumulated daily stresses. Takes a lot of "homework" too.
PT sessions alone just won't do it all.

Posture overall and upper body alignment?
That awareness is a constant also.
Forward head/forward shoulders close down on all vascular & nerves that run thru the BP area.

check out our useful sticky thread tons of info & PT, body work, articles , videos
http://neurotalk.psychcentral.com/thread84.html

Sharon Butlers website has a lot of info about all RSIs & TOS - www.selfcare4rsi.com

You can turn it around but takes time & a lot of work.

These are good things for offsetting the "forward" postures & to open up the chest.




lay on foam roll or large towels rolled up tightly (lengthwise down the spine) - a pillow if needed for neck comfort - then just relax with arms at a comfortable position