Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Dual lead left - sided pacemaker is stable in position . There is a moderate to large left pleural effusion with overlying atelectasis . Left base consolidation is not excluded . Mild right base atelectasis is seen . The patient is somewhat rotated . Cardiac and mediastinal silhouettes are grossly similar compared to the prior study .
    OUTPUT:
    
Left base opacity worrisome for pleural effusion and atelectasis .