Left Lobe Atelastic

I'm a 34 year old female who has Viral Cardiomyopathy. During a chest CT it was discovered that I had lower left lobe atelasticis (sorry about spelling). What I don't know is if this could have been there all my life. I had croup when I was a baby. They tell me it doesn't have anything to do with my heart failure, but it just seemed coincidental that it's the left lung near the heart. My heart is not enlarged, but the upper limits of normal. Could this be scarring from something such as the croup, or another illness and not heart related? Thanks so much.

[National Jewish]

The first step should be to locate previous x-rays to determine if the atelectasis has been present for some time or is a more recent development. Some of the viruses that cause cardiomyopathy can also cause atelectasis, but it is possible that the atelectasis is unrelated to the cardiomyopathy, especially in the absence of a normal sized heart.
Atelectasis could be due to a childhood infection like croup if the following apply:
1) The atelectasis is present on X-rays taken two or more years ago;
2) There has been no indication of the atelectasis being a source of recurrent infection; and
3) The atelectasis is small.
On the other hand, atelectasis should be further evaluated if the following apply:
1) The atelectasis is large;
2) The atelectasis has been associated with infection; or
3) The atelectasis is clearly a recent occurrence.