CPT® code(s) for a senario, pulmonary walking stress test.

I am having a hard time finding the code for the following. I'm hoping someone can help me with this one.

ENTRANCE DIAGNOSIS: Dyspnea. He gave a broad rating of 5 by the time he finished: it was 3 at the beginning and showed some discomfort or effort to do this. He was able to walk 6 minutes nat a slow pace without stopping. He did have some wheezing, some coughing, and was able to go 300 feet, which for this age group is relatively poor exercise tolerance. The O2 sats never dropped below 92%. This patient does not need oxygen therapy with this form of exercise.

Any suggestions?

Thanks

Karen