Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left chest wall defibrillator has a single lead terminating in the right ventricle . There is atelectasis in the right middle lobe as seen on CT in ___ . The heart is top normal . The mediastinal and hilar contours are normal . There is no pleural effusion or pneumothorax . There is no pulmonary edema .
    OUTPUT:
    
Chronic atelectasis in the right middle lobe but no evidence of pneumonia .