Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are slightly low . There is minimal opacity at the periphery of the left base which likely reflects atelectasis . Left chest wall pacemaker has leads terminating in the right atrium and right ventricle . Heart size is exaggerated by AP technique but there is likely mild cardiomegaly . The mediastinal and hilar contours are normal . There is no large pleural effusion and no pneumothorax .
    OUTPUT:
    
1 . Atelectasis at the left base ; pneumonia thought less likely but correlation for infectious symptoms is recommended . 2 . The heart is larger since the prior study now with mild cardiomegaly .