Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is markedly enlarged . The aorta is tortuous . There is a dual - lead pacer with leads terminating in expected position in the right atrium and right ventricle . There is nonspecific pleural and parenchymal scarring at the left lung base . Otherwise , the lungs are clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Nonspecific pleural and parenchymal scarring at the left base . No findings specific for past or active TB infection .