Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single lead from an implantable defibrillator is unchanged in position compared to the prior study . Lung volumes are slightly improved compared to the prior study . The heart remains mildly enlarged . Previous median sternotomy noted . With evidence of coronary artery bypass grafting . No consolidation , pneumothorax or pleural effusion seen . Moderate degenerative changes in the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary process seen .