Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A left - sided pacemaker projects leads into the right atrium and ventricle . The heart is mildly enlarged . The hilar and mediastinal contours are unchanged . Central pulmonary vascular prominence appears minimally changed , though , in combination with lower lung volumes , likely represents overall improvement . There is no longer any appreciable edema . There is no pneumothorax . A small left pleural effusion is unchanged . A previously seen a very large hiatal hernia is not easily seen on the current study , due to lack of intraluminal gas .
    OUTPUT:
    
1 . Unchanged small left pleural effusion . 2 . Central pulmonary vascular congestion has improved . No overt edema .