Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Right chest wall pacing leads and in the right atrium and right ventricle , unchanged . The heart is top - normal in size . Prominence of the left mediastinum is unchanged and may represent pulmonary artery enlargement . The lungs are grossly clear . There is no pneumothorax or pleural effusion .
    OUTPUT:
    
No evidence of pneumonia .