Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The left subclavian pacemaker seen with leads terminating within the right atrium and right ventricle . Unchanged mild cardiomegaly . Normal lung volumes . No pneumothorax , no pleural effusion , no pulmonary edema . Mediastinal borders and hilar structures are normal .
    OUTPUT:
    
Pacemaker leads in appropriate position .