Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable AP chest radiograph demonstrates low lung volumes . There is an enlarged heart with mild pulmonary vascular congestion . No focal consolidation concerning for pneumonia is identified . Patient is rotated . Intact median sternotomy wires as well as surgical clips along the left mediastinum and about the right atrium noted . A right pectorally placed dual lead pacer is identified with its leads terminating in the right atrium and right ventricle . Patchy opacities at the lung bases most compatible with atelectasis . Heart size is enlarged . Allowing for suboptimal technique , no large pleural effusion is identified .
    OUTPUT:
    
Mild cardiomegaly with mild pulmonary vascular congestion . Probable bibasilar atelectasis .