Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are decreased accentuating the bronchovascular structures . The heart is mildly enlarged and unchanged since prior examination . There is chronic elevation of the left hemidiaphragm with adjacent atelectasis at the left lower lung . No focal consolidation is identified in the upper lungs . There is no overt pulmonary edema . No definite pneumothorax . Patient is status post median sternotomy and CABG .
    OUTPUT:
    
Left lung base atelectasis . No congestive heart failure .