Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable chest radiograph is obtained . The heart is moderately enlarged . There is a retrocardiac density again noted likely representing a hiatal hernia . There is no evidence of CHF or pneumonia . There is a tiny left pleural effusion noted . No pneumothorax . Bony structures are intact .
    OUTPUT:
    
Moderate cardiomegaly with tiny left pleural effusion . Hiatal hernia redemonstrated .