Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded and show a retrocardiac opacity with a moderate effusion . The cardiac silhouette is enlarged . The mediastinal silhouette and hilar contours are normal . There is a moderate left pleural effusion . A left - sided pacer wire right atrial lead traverses the left - sided SVC and the coronary sinus . The right ventricular lead is appropriate .
    OUTPUT:
    
Increased moderate left - sided effusion with associated atelectasis .