Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and cardiac valve replacement . The cardiac and mediastinal silhouettes are stable with the cardiac silhouette enlarged . No focal consolidation is seen . Evidence of a hiatal hernia is seen with retrocardiac air - fluid level . The aorta is calcified .
    OUTPUT:
    
No acute cardiopulmonary process .