Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A left - sided AICD / pacemaker device is again noted with leads terminating in the right atrium , right ventricle , and coronary sinus . Epicardial leads are also noted . The heart remains moderate to severely enlarged but stable . Mediastinal contour is unchanged , with tortuosity of the thoracic aorta again noted . Calcifications of the thoracic aorta are most pronounced at the arch . The hilar contours are unchanged , with mild pulmonary vascular congestion again noted , not significantly changed in the and prior study . Small left pleural effusion which appears to be partially loculated laterally is not significantly changed in the interval , with continued retrocardiac opacity likely reflective of atelectasis . The right lung otherwise is grossly clear , and no pneumothorax is detected . There are multilevel degenerative changes of the thoracic spine .
    OUTPUT:
    
Mild pulmonary vascular congestion , small left pleural effusion , and retrocardiac opacity likely atelectasis . Findings are all similar when compared to the prior exam .