Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal radiograph of the chest shows an enlarged cardiac size with bibasilar atelectasis , worse on the left . Concurrent pneumonia at the left base is not totally excluded . Small left pleural effusion is likely . Right chest wall pacemaker with right atrial and ventricular leads appropriately positioned . Heart size is enlarged . Mediastinal contour is within normal limits .
    OUTPUT:
    
Bibasilar atelectasis with possible concurrent pneumonia at the left lower lobe , in the appropriate clinical setting . Small left pleural effusion .