Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest film ___ at 13 36 is submitted .
    OUTPUT:
    
A left - sided pacer remains in place . A right subclavian PICC line has its tip at the cavoatrial junction / proximal right atrium . There has been interval removal of the right subclavian Swan - Ganz catheter . There are layering bilateral effusions with patchy airspace opacity , left greater than right , which most likely reflects compressive atelectasis , although pneumonia can not be excluded . There is mild but improved interstitial edema . No pneumothorax . Status post median sternotomy with stable postoperative cardiac and mediastinal contours .