Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph is obtained . Patient is known to have extensive underlying emphysema . Opacity in the left lung base is most likely reflective of a pleural effusion and possibly subjacent atelectasis , though pneumonia can not be entirely excluded . There is also a small right pleural effusion . Overall findings appear slightly progressed at the left lung base compared with prior study . The heart remains mildly enlarged . No pneumothorax is seen . Bony structures are intact . Left chest wall pacer device is again seen with lead tips extending into the right atrium and right ventricle .
    OUTPUT:
    
Increased opacity at the left lung base which could reflect increasing consolidation or effusion . Small right pleural effusion is stable . Severe underlying emphysema with mild cardiomegaly .