Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left - sided AICD / pacemaker device is noted with single lead terminating in the right ventricle . Borderline enlargement of the heart size is demonstrated with a left ventricular predominance . The mediastinal and hilar contours are unchanged and within normal limits . The pulmonary vasculature is normal . Small left pleural effusion is noted . No focal consolidation or pneumothorax is identified . There are mild degenerative changes in the thoracic spine .
    OUTPUT:
    
Small left pleural effusion .