Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were reviewed and compared to the prior study . A dual - chamber pacemaker located in the left hemithorax has leads ending in the right atrium and right ventricle . A new retrocardiac opacity could represent pneumonia given the clinical history . The heart size is normal and there is no vascular congestion , pleural effusion or pneumothorax .
    OUTPUT:
    
New retrocardiac opacity could represent pneumonia considering the clinical history .