Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . There is status post sternotomy and the presence of multiple surgical clips in the anterior mediastinum are indicative of previous bypass surgery . Moderate cardiac enlargement is present . There is some upper zone redistribution pattern in the pulmonary circulation , but no signs of advanced interstitial or alveolar edema are seen . Also , the lateral and posterior pleural sinuses remain free from any fluid accumulation . No evidence of new discrete pulmonary parenchymal infiltrates are seen . No pneumothorax can be identified in the apical area . Moderate degree of degenerative change is noted in the thoracic spine which shows a mildly accentuated kyphotic curvature . Our records include a previous chest examination dated ___ . Moderate cardiac enlargement existed already at that time , but the patient had no signs of bypass surgery . The patient was postoperative to hernia repair and had bilateral chest wall emphysema with suspicious mediastinal emphysema . These signs have disappeared .
    OUTPUT:
    
Moderate cardiac enlargement , mild degree of pulmonary congestion , but absence of new acute infiltrates . Evidence of previous bypass surgery .