Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Left chest wall pacer device is unchanged in position with leads extending to the region of the right atrium and right ventricle as well as the coronary sinus . The heart remains moderately enlarged . Subtle opacity is seen within the left mid lung which could represent an early developing pneumonia . Alternatively , asymmetric pulmonary edema is difficult to exclude in the correct clinical setting . Mild pulmonary vascular congestion is present . No large effusion or pneumothorax . Bony structures are intact . Subtle deformity of the right humeral neck likely reflect an old injury .
    OUTPUT:
    
Stable moderate cardiomegaly . Mild congestion noted with subtle opacity in the left mid lung which could represent a developing pneumonia versus asymmetric edema . Please correlate clinically .