Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post coronary artery bypass graft surgery . Single - lead pacemaker device appears unchanged . The heart appears mild to moderately enlarged . Cardiac , mediastinal and hilar contours appear stable . There is a similar mild to moderate , diffuse interstitial abnormality . Most likely etiology is interstitial pulmonary edema without substantial change . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Findings suggest mild to moderate interstitial pulmonary edema . Cardiomegaly .