Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright chest film dated ___ at 06 :36 is submitted .
    OUTPUT:
    
Left pacer remains in place . The heart remains stably enlarged . Mediastinal contours are unremarkable . There is persistent perihilar vascular congestion with no evidence of overt pulmonary edema . There is possibly a small left effusion . No pneumothorax is appreciated . Patchy bibasilar opacities may reflect atelectasis although pneumonia or aspiration can not be entirely excluded . Clinical correlation is advised .