Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest were acquired . There is redemonstration of a left - sided pacemaker with unchanged positioning of right atrial and right ventricular leads . There is minimal bilateral lower lung atelectasis . The lungs are otherwise clear . The heart size is top normal , unchanged . The thoracic aorta is slightly tortuous , as before . There are no pleural effusions . No pneumothorax is seen . Multilevel degenerative changes of the thoracolumbar spine are seen .
    OUTPUT:
    
No acute cardiac or pulmonary process .