Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest demonstrate a new left chest wall pacer defibrillator with appropriately placed right atrial and ventricular leads . No mediastinal widening is noted . Otherwise , compared to the prior study , there has been marked improvement in pulmonary edema with continued mild bibasilar atelectasis . Previously enlarged cardiac size is now normal . No pleural abnormalities are seen .
    OUTPUT:
    
Status post atrioventricular pacer defibrillator with satisfactory positioning of leads and no pneumothorax or mediastinal widening .