Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-erect chest radiograph ___ at 05 :56 is submitted .
    OUTPUT:
    
A right - sided single lead pacer remains in place with the lead appearing intact and terminating over the expected location of the right ventricle . The heart is enlarged favoring cardiomegaly , although pericardial effusion can not be excluded . Interval increase in lung volumes with prominent perihilar vasculature but no overt pulmonary edema . Patchy opacity at the right medial lung base may represent atelectasis , although early pneumonia or aspiration should also be considered . This can be better assessed on followup imaging . No pneumothorax .