Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable AP chest radiograph demonstrates he right pectorally placed pacer , its leads in unchanged position projecting over the right atrium and right ventricle . There appears to be improved aeration at the bilateral bases . Cardiomediastinal and hilar contours are stable in appearance . No appreciable change in degree of mild vascular congestion .
    OUTPUT:
    
No appreciable change in degree of mild vascular congestion .