O2 Levels

[Lynn8889]

I've recently started seeing a Pulmonologist after my primary doctor ordered a Pulmonary Function Test which came back abnormal.My doctor mentioned Restrictive Lung Disease and also that my diffusion capacity was very concerning.  Sorry, I do not have numbers or the report.  She then ordered a High Res. CT.Findings state: Calcified mediastinal and left hilar lymph nodes are present consistent with previous granulomatous disease.  Calcified granulomas are also present in the left lung.  There is no pulmonary infiltrate identified.  IMPRESSION: Evidence of old granulomatous disease. No active air space or intertital disease indentified.  
Anyway, I started seeing a pulmonologist a few weeks ago, and he put the clip on my finger to check my oxygen level.While sitting and resting, it is 100.  He said we were going for a little walk with the clip on, as soon as I got up and started walking (not even 1 minute after walking....he stopped me....the level dropped to 80).So we put the clip on the other hand and tried again.Same thing happened.  It dropped quickly.   He thought maybe I could have Pulm. Hypertension and he ordered a right heart cath.They ended up doing a right and left.Everything was normal.Pulmonary pressure normal.  A few weeks ago, I had a holter monitor and it showed 272 multiformed ventricular ectopic beats (I noticed irregular beats and my dr. had me on a 24 monitor).  
My questions are:
1) What do you make out of the CT report?
2) If not PH, what could cause the O2 levels to drop like that? I do get SOB.
3) What next step would you take if you were my Dr?

[National Jewish]

The high resolution CT (HRCT)

[Lynn8889]

Thanks for your time in answering my question?  It's much appreciated!

[Lynn8889]

BTW..I am a 35 yr old, Female, 5'10, 120 lbs, always been a non-smoker.