Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to ___ , a left - sided pacemaker has been placed , with lead tips over the right atrium and right ventricle . The cardiomediastinal silhouette is unchanged . No CHF , focal infiltrate , effusion , or pneumothorax is detected .
    OUTPUT:
    
Interval placement of left - sided pacemaker with lead tips over right atrium and right ventricle .