Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Dual - chamber pacemaker leads are in unchanged position from the prior radiograph heart size and mediastinal contours are normal . Lungs are clear without evidence of pneumonia . There is no pleural effusion or pneumothorax . Blunting of the left costophrenic angle is chronic .
    OUTPUT:
    
No evidence of pneumonia or heart failure .