Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral chest radiograph demonstrates clear lungs . No focal opacity to suggest pneumonia is identified . A dual lead chest wall pacer - defibrillator is identified its leads in similar position when compared to prior study again identified is a mitral valve replacement . Sternotomy wires appear intact . Heart is enlarged though stable . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No acute intrathoracic abnormality . Stable cardiomegaly .