Could there be negative affect on lung function slightly below average performance 1yr after being on heart and lung machine for Open Heart Surgery?

Yes, brain, heart & brain, etc. because clots form in blood while being moved through the long plastic, non-endothelium lined tubing between your chest & within the heart lung machine a few feet away from your body. Thus heparin is infused into the blood shortly after leaving you body (too much would cause excess bleeding) yet can never prevent all microscopic clots which block microcirulation after returned to body.
Unusual. There are multiple reasons for lung dysfunction after cardiac surgery especially if significant transfusions were needed and time on bypass was long. Most of these factors resolve over 1-3 months if healing is adequate and rehab is successful. Diaphragm dysfunction or lung trapping may be reasons for prolonged problems. Get a pulmonary evaluation at this point unless recovery slowed by some issue.
To a degree. depending on ore existent situation: obstructive lung disease,recent smoking, heart failure and congestion. It is common to have peri operative atelectasis, fluid shifts, blood or fluid in pleural spaces.

Related Questions

Will I be able to talk to the perfusionist before my open heart surgery. I have a lot of questions about cognitive problems from bypass machine.?

Possibly. Your surgeon should also be able to address these questions, as they are certainly well-versed in the complications related to bypass, and also what sort of bypass will be needed for your case. On the other hand, i'm certain most centers could easily arrange for you to spam with the perfusionist... Read more...
If you ask. Usually the members of the heart team are happy to talk to you - if they know you want to do it. Ask your surgeon to see if he can arrange it. Read more...

Why are the following tests done preoperatively for open heart surgery? Echo...chest X-ray.....pfts.....and urinalysis?

Here are some ... All preoperative history-taking, physical exam, tests - imaging or bloods or pulmonary, are confirming anatomical and functional status of body and concerned organ of treated target & predicting intra- / postoperative risks so to take precaution to minimize / avoid intra- / postop complications, leading to a best possible recovery, especially for major surgery like open heart surgery. Detail? Ask. Read more...
Preparation. You are having surgery for a reason. Preparation makes the surgery safer by finding issues that would be problems if they were not known. Overall, the better prepared you and you surgeon are, the better the results. Read more...