Follow up to isolated DLCO

This is the woman with low DLCO. The stress echo came back as no evidence for ischemia, (although the HR was only 130, which is 76% of the predicted max - she stopped because of pain in her hips. You will recall she had b/l hip replacements). Anyway, the only thing left is an EMG (reminder that her MIP's, MEP's and MVV were all normal). Any other ideas? Her low DLCO and dyspnea are real, despite the negative workup thus far.