COPD & Emphysema Support Group
COPD is a progressive disease characterized by airflow obstruction or limitation. Emphysema is characterized by loss of elasticity of the lung tissue, destruction of structures supporting the alveoli and of capillaries feeding the alveoli. Both have symptoms that include shortness of breath, among other respiratory troubles. If you are a COPD or Emphysema sufferer, join...
http://www.mayoclinic.org/symptoms/hypoxemia/basics/causes/sym-20050930
Anything below a SpO2% of 88% (actually 90% since Oximeters are usually +/- 2%) is considered dangerous. Hopefully, you are still on Oxygen therapy and have purchased an Oximeter. You can help your doctor by carefully monitoring and logging your SpO2%, diet, other medications (prescriptions, OTC, or supplements); periodically and before and after activity. A pattern may emerge or the fact there doesnt appear to be a pattern or obvious association can help with the diagnosis.
i have weird results on my PFT tests because i have both COPD (emphysema) & PF (pulmonary fibrosis/ild), but they both clearly show up on an HRCT.
(my FEV1 is higher than normal for COPD, but my DLCO is low showing that the 02 gets in my lungs but doesn't go from my lungs to my blood stream, so i need to wear 02 also)
and the echo you had done would have shown if you had PH (pulmonary hypertension).
I'm not sure how they checked for blocked arteries, but i assume your dr is doing all the tests to see what is causing it.
sorry i'm of no help, but I do want to welcome you here and I hope they find the cause.
in the meantime thank goodness for oximeters & supplemental 02.
ps.Keep active as the less i do the worse my lungs seem to get.