Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs demonstrate intact sternotomy wires and a new left chest pacemaker with the single lead overlying the right ventricle . There is no pneumothorax . The cardiomediastinal silhouette is unchanged . A new retrocardiac opacity likely represents atelectasis . There is a new small left pleural effusion .
    OUTPUT:
    
1 . New left chest pacemaker with a single lead overlying the right ventricle . No pneumothorax . 1 . A retrocardiac opacity is likely atelectasis . New small left pleural effusion .