Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Median sternotomy wires appear intact . Mitral valve replacement appears in place . Two lead cardiac pacemaker appears unchanged . There is mild bibasilar atelectasis and increased interstitial markings . Otherwise , the lungs are without a focal opacity . There is no pneumothorax . Heart remains mildly enlarged but stable . Old rib fractures are again noted .
    OUTPUT:
    
There is suggestion of early interstitial edema . Otherwise , post - surgical changes appear stable .