Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and right - sided pacer placement with leads terminating in the right atrium and right ventricle . Low lung volumes are present . Heart size is mildly enlarged and accentuated by the low lung volumes . Convexity at the right cardiophrenic angle could reflect a hiatal hernia . Hilar contours are unremarkable . Crowding of the bronchovascular structures is present with probable mild pulmonary vascular congestion . Patchy opacities in the lung bases may reflect areas of atelectasis but infection or aspiration can not be excluded . No acute osseous abnormality is detected .
    OUTPUT:
    
1 . Low lung volumes with bibasilar patchy opacities , potentially atelectasis . Infection or aspiration can not be excluded . 2 . Convexity at the right cardiophrenic angle could potentially reflect a small hiatal hernia .