Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Dual - lumen right central venous catheter tip projects over the low SVC , unchanged . Left single lead ACID is unchanged in position . The patient is status post median sternotomy . Numerous mediastinal clips and epicardial pacing wires are unchanged . Lung volumes remain low . Interval increase in left lower lobe opacity likely reflects a combination of atelectasis and mild edema . Bilateral pleural effusions are small , perhaps slightly increased from the prior exam . The heart moderately enlarged .
    OUTPUT:
    
Findings most consistent with mild volume overload . No pneumonia .