Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Transvenous pacemaker leads are in appropriate position in the right atrium and right ventricle . Mild cardiomegaly is stable . Mild blunting of the right costophrenic angle may represent effusion or scarring . The lungs are clear . Mediastinal and hilar contours are normal . Pleural surfaces are normal . No pneumothorax , mediastinal widening , or evidence of hemothorax .
    OUTPUT:
    
Appropriate positioning of transvenous pacemaker leads in the right atrium and right ventricle . No pneumothorax , mediastinal winding , or evidence of hemothorax .