Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . Analysis is performed in direct comparison with the next preceding similar study ___ ___ . The heart size remains within normal limits . No typical configurational abnormalities identified . The thoracic aorta is generally widened to a moderate degree and shows some calcium deposits in the wall at the level of the arch , but there is no evidence of any local contour abnormality . The pulmonary vasculature is not congested . Similar as on the previous examination , the central pulmonary vessels are rather prominent and widened , a finding which may be related to chronic pulmonary hypertension . There is no evidence of any acute pulmonary infiltrate . Similar as on the preceding examination , a permanent pacer ( ___ ) is identified in left anterior axillary position , seen to connect to a single intracavitary electrode , the tip of which reaches into the area of the apical portion of the right ventricle . Skeletal structures demonstrate mild - to - moderate degenerative changes mostly in the mid portion of the thoracic spine , but no other gross skeletal abnormalities are identified .
    OUTPUT:
    
Single electrode permanent pacer in unchanged appropriate position in comparison with the next preceding similar study ___ ___ . Stable chest findings .