Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left - sided pacemaker device is re - demonstrated with lead terminating in right ventricle . Heart size remains moderately enlarged . The aorta is unfolded and diffusely calcified , similar compared to the prior exam . No overt pulmonary edema is present . Increased interstitial markings within the lung bases may reflect atelectasis . No focal consolidation is noted . No definite pleural effusion or pneumothorax is seen . No acute osseous abnormality is detected .
    OUTPUT:
    
Mildly increased interstitial markings at the lung bases may be due to atelectasis .