Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes with subsegmental atelectasis in the lower lobes . Prominence of the pulmonary vasculature can be related to crowding from low lung volumes or mild elevated pulmonary venous pressure . Mild cardiomegaly . No effusions or pneumothorax . Prior sternotomy , CABG and implanted left chest wall Holter monitor .
    OUTPUT:
    
Prominence of the pulmonary vasculature can be related to crowding from low lung volumes or mild elevated pulmonary venous pressure . Mild cardiomegaly .