Chest CT

[grace77]

I have a mito. myopathy with the resp. muscle weakness. I had a CT chest last year that showed an enlarged PA and a nodule . So my pulmo. had it repeated in June.  My PFT's show a restrictive process with decreased DLCO (60's) but have stayed stable. My MIP and MEP are very low ( 18 % & 21%). I had a RHC in Jan. to r/o PH. The pressures were nl (14) although the FICK was slightly elevated. I have documented hypoventilation and hypercapnia at night. I am supposed to wear a cpap but unable to tolerate this. Also, I have never smoked. Not sure why the lungs are hyperinflated with emphysematous changes.
Findings:
Left infrahilar calcified lymph node is seen. No pericardial or pleural effusion. Main PA measures 3.6 cm. Lungs are hyperinflated. mild emphysematous changes are seen. No pneumothorax. Mild bronchial wall thickening.
Again identified is a tubular/nodular opacity in the medial aspect of the LUL just superior to the hilum. An additional curvilinear tubular shaped opacity is evident in the LUL just superolateral to this lesion. Subsegmental atelectasis along the left major fissure. Calcified lymph node is seen within the LUL/ No infiltate.
Additional 4 mm rounded opacity is identified in the posterior aspect of the LUL.
Impression:
1. Likely scattered AVM's of the LUL. Further evaluation with CTA of the chest is recommended.
2. Pulmonary nodule in LUL. F/u CT in 12 mos is recommended.

Now on last year's CT , there were no AVM's. What is a CTA? My dr, of course, has not communicated to me that this was recommended. Are AVM's dangerous in the lung? I know people have them in the colon and brain etc and they can cause bleeding. Never heard of them in the lungs.
The nodule concerns me somewhat. Also even though my RHC was nl, the PA is enlarged. Do you have any theories as to why this would be enlarged?
Thanks. I am not sure if I need to call my pulmonologist to ask about the AVM's and recommended CTA.

[David Tinkelman, M.D.]

Let me attempt to answer your questions in order and then make suggestions.

The evidence you cite seems to confirm the diagnosis of mitochondrial myopathy.  It is unfortunate that you have been unable to use the CPAP at night as the resultant hypoxia is stressful for all your organs, especially your heart and brain and could also be a cause of pulmonary hypertension. My first suggestion is that you and a sleep specialist make a concerted effort to find a means of applying pressure to your airways, other than the conventional mask.   It is conceivable that your PA pressure would be elevated at night and not while you are awake; this could account for the normal PA pressure at RH cath.  Nocturnal hypoxia could thus account for the slight enlargement of your PA on CT.  If you do indeed have AV malformations, that and hypoxemia could account for the elevated FICK (assume you are referring to cardiac output).

The recommendation of a 12 month follow-up of the nodule (in a non-smoker) is appropriate.  

I agree that the appearance of hyperinflation of your lungs is surprising, if not inconsistent with your chronic hypoventilation.  This is a CT interpretation, however and I believe that a measurement of lung volumes by plethysmography might be a better way of assessing hyperventilation.  I assume also that the reduced DLCO is on the basis of low lung volumes, poor air exchange, the AV malformations and micro, if not macro, atelectasis.  The “scattered AVM’s of the LUL, if confirmed, are worrisome, as they especially if large, subject a person to the risk of embolization (clots) to other parts of the body, including the brain.  These structures  are abnormal vascular structures that provide a direct capillary-free communication between the pulmonary and systemic circulations.  This complication  can be limited if the underlying condition is recognized and treated with embolization using metal coils, balloons, or plug devices, to abolish blood flow through these structures, the treatment of choice for almost all patients.  Percutaneous transcatheter embolization, using metal coils, balloons, or plug devices are the treatment of choice for most individuals.
AV Malformations are noteworthy as they are often associated with an inherited vascular disorder hereditary hemorrhagic telangiectasia (HHT, or Osler-Weber-Rendu syndrome).  You should discuss this possibility with your doctors. The malformations are best confirmed by Spiral (or helical) CT.  The radiation burden is greatly lessened and the resolution improved by the use of newer multislice (multidetector) CT protocols, which limit x-ray exposure to a single short breath-hold scan, and which allow three-dimensional reconstructions of the images.  CTA is  Computed Tomography Angiography, another way to visualize AV malformations..  
Yes, you should call your pulmonologist to decide upon the confirmation and treatment of the malformations which do, as described above, pose a threat of clots developing and traveling to almost anywhere in the body.
To summarize, do work hard to make the CPAP work for you.  Follow the advice of your pulmonary specialist and ask him/her about the HHT, mentioned by me above.
Good luck

[David Tinkelman, M.D.]

More information from the Dr.:

There are a number of causes of the “lot of shortness of breath, worse with exertion…” you describe.  The most likely is that the mitochondrial disorder makes it impossible for your breathing to keep up with the increased demand required when one exercise.  It is also possible that your blood oxygen levels fall or your carbon dioxide levels rise precipitously with exertion or both, causing your respiratory center to send stimuli (signals) to the respiratory muscles, that are incapable of the normal response, increased ventilation.  Another possible cause would be the AV malformations that may “shunt” an increased amount of blood when you exert yourself, the shunt being blood that does not come into contact oxygen (breathed into your lungs) as it passes through your lungs.  By means of lung function testing, at rest and with exertion, your pulmonary doctor may be able to separate out the cause(s) of your worsened shortness of breath, even with relatively mild exertion.

Don’t hesitate to ask your doctors the same questions that you have asked in this forum.

[grace77]

Thanks so much for all your help. I did get in touch with my pulmo. who thought (and I quote) "The AVM's are nothing to worry about but he would get a CT with contrast at my next visit which will be in December. It is interesting that you would mention the possibility of the pressures rising at night because this is what my PCP thinks also. I have had an issue with bilateral lower extremity edema( with venous insufficiency ruled out) over the last year. I am having to take 40 mg Lasix to control it. I feel sure it all ties into the lung issues somehow.
I have an appt with my sleep specialist in a few weeks. The last one I saw just told me to go on the internet and find a mask I thought would work. Needless to say, I changed docs.
I did have an exercise stress test that documented poor exercise tolerance. One more question - can one have PH with just the pressures being elevated at night even though it would be difficult to assess this short of having a SWAN put in to monitor this?
Thanks again for making my concerns feel validated.

[grace77]

I was reviewing some old med records and I found a CT chest report from 2005 that was normal with no mention of nodules,avm,large PA etc.

[grace77]

I also have a lot of shortness of breath,worse with exertion and even at rest. At rest, it is more the air hunger sensation. I also have the air hunger at night when I will have to get up because I feel like I cannot breathe.

[grace77]

I forgot to add I am a 45 yr old female.