fluctuating oxygen saturations

[loree147]

I am a 48 year old female with a 4 year history of shortness of breath, dizziness and dry cough. I have had pulmonary pressures of up to 50. I had an RHC done back in 2009 and it was normal(mean pressure was 18). Everything else has been ruled out. Last October I had a TIA and on the MRI, it showed 3 previous strokes. They do not know why. I went to cardiac rehab where they put me on a treadmill with an oxygen saturation monitor. My sats were below 90 the whole time dropping to a low of 83. The heart rate seemed accurate so I can only assume it was accurate. I got a small pulse oximeter and brought it home. My sats seem to drop when I do something with resistance like get out of a chair. While just walking, they seem to fluctuate anywhere from 89 to 99. Is this normal? I wonder if my circulation is impaired when walking or something and its not really a lack of oxygen. I don't know what to think and neither does my doctor. They don't do RHC's with exercise in Canada so that cannot be ruled out. Any thoughts?

[loree147]

Thanks. That does help. I had seen a pulmonologist who had done an exercise test and he said it was abnormal as my diastolic BP had gone up instead of down. He was going to send me to a PH clinic in Quebec to get reviewed again. This was last fall. He really wanted an exercise test done with the RHC but knew it wouldn't get done in Canada. He strongly felt the pulmonary pressures were going up when I exercised. I then had the TIA so it kind of went on the back burner and I have read much information that states no one is convinced exercise induced PH even exists. That makes me feel better. I will speak to my doctor about your suggestions.

[Jonathan D. Rich, MD]

Hello and welcome to the forum.

First, I am terribly sorry to hear about the struggles you have been dealing with for the past few years.  I will try my best to offer some advice.

Let's start with the subject of this forum which is pulmonary hypertension.  Although it is possible that things have changed since 2009, the fact that you had a RHC with a mean PA pressure of 18 mm Hg suggests you do NOT have pulmonary hypertension (18 is about as normal as it can get).  I dont even care what the pressures would/could/might do during exercise...you do not have PH.  This should make you happy :)

Ok, as far as what you do have, I of course will not be able to tell you for sure without seeing you in the office.  However, first and foremost, you need to have a thorough pulmonary (lung) evaluation if you havent already.  Your symptoms coupled with your low oxygen saturations would lead me to evaluate your lungs thoroughly.  This would likely include pulmonary function tests (PFTs) and a high resolution CT scan of your chest.  It might also be reasonable to try to exclude "blood clots" in your lungs which they can do at the time of the CT scan of your chest.  Finally, another test that can sometime be performed to sort out "heart versus lungs" is called a cardiopulmonary exercise test (aka CPX).  But, I would start with the more straightforward tests above first.

Regarding your TIA (and strokes), this also should be investigated.  Although unlikely, one possibility to tie the two issues together (ie lungs and strokes) is if you have a small hole in your heart that allows the right side to communicate directly with the left side, this can potentially result in occasional drops in your oxygen saturation and also might allow a small clot to travel to the left side of your heart (which could then potentially go to your brain).

I mention the above possibilities not to scare you in any way but more to emphasize that you need a thoughtful evaluation and that I would find it highly unlikely to not be able to provide you with a diagnosis if such an evaluation is performed.  

Hope this helps and wishing you the best.

Dr. Rich