I am a 33 y.o. female with generalized dysautonomia and severe gastroparesis. I have severe venous pooling in my splanchnic bed and dependent limbs (46%) when seated upright as seen in my radionuclide hemodynamic study. (All testing mentioned herein performed while on Midodrine QID; all meds requested to be withheld for autonomic testing by lab were stopped prior to testing as required.) A venous physiology (plethysmography) study was ordered and performed. Results of the venous outflow and dependent venous refilling segments were normal. However, the exercise venous plethysmography revealed reduced post-exercise refill volume in my left leg, reduced ejection fraction in my left leg, and reduced post-exercise VFT90 (??) in my left leg ... suggestive of venous valvular incompetency. (My one neurologist said it looked like an "old lady" leg.) My right leg seemed normal even on the exercise portion, though. Any thoughts on why the valves in one leg would be OK and the valves in the other leg would be so bad? Any reason why it would show up on the exercise portion in particular?