Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post aortic valve replacement . A double - lead pacemaker / ICD device has leads terminating in the right atrium and ventricle , respectively . The heart is again enlarged . The aorta is tortuous and calcified . There is no definite pleural effusion or pneumothorax . An extensive interstitial abnormality involving the mid - to - lower lung is more extensive than before and there is a similar new abnormality , although not as extensive , involving the right lower lung , particularly the right middle lobe . Elsewhere , lung parenchyma is mostly spared . Mild degenerative changes appear similar along the thoracic spine .
    OUTPUT:
    
Worsening asymmetric interstitial abnormalities involving the lung bases , greater on the left than right . Although an acute on chronic process is possible , it seems more likely that there is a background process of worsening interstitial lung disease to explain the appearance .