Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Left chest wall pacer device is again noted with leads extending into the region of the right atrium and right ventricle unchanged . Aortic valve replacement again noted . Midline sternotomy wires are present . There is mild hilar congestion and mild pulmonary edema . Opacity at the right lung base likely represents a small pleural effusion , difficult to exclude a superimposed pneumonia . Elevated right hemidiaphragm is chronic . Heart size is stably enlarged . Mediastinal contour is unchanged . Bony structures are grossly intact .
    OUTPUT:
    
Congestion with mild edema and small right pleural effusion . Difficult to exclude pneumonia in the right lower lung . Chronic right hemidiaphragm elevation .