Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest film ___ at 19 :27 is submitted .
    OUTPUT:
    
Interval placement of a dual lead left - sided pacer with the leads terminating over the expected location the right atrium and right ventricle , respectively . There is crowding of the vasculature given the low lung volumes . Patchy opacity at the right base likely reflects atelectasis . Linear lucency at the left apex could reflect a tiny pneumothorax . Followup imaging should be considered . Heart remains stably enlarged . No evidence of pulmonary edema . Prominent calcification of the left first costochondral junction unchanged .