Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright frontal and lateral views of the chest were provided . Midline sternotomy wires and mediastinal clips are again noted . A prosthetic aortic valve is noted . There is a left chest wall pacemaker with leads extending into the region of the right atrium and right ventricle . There is a stable appearance of the right lung base pleural thickening and associated scarring . Retrocardiac opacity is again noted compatible with a small hiatal hernia . Heart size top - normal . Mediastinal contour is unchanged and within normal limits . The bony structures are intact .
    OUTPUT:
    
No acute intrathoracic process .