Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The left chest tube is in unchanged position , crossing the midline on the frontal view and located retrosternally on the lateral view . Epicardial pacer wires in dual - chamber pacemaker leads are in satisfactory position . Previously seen left apical pneumothorax is not well appreciated secondary to exclusion from the field - of - view . Right apical pneumothorax is small . Moderate left basilar atelectasis persists .
    OUTPUT:
    
Left chest tube within the thorax , in the retrosternal space , crossing the midline , impinging on the anterior mediastinum .