Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A left pectoral cardiac pacer has single lead terminating in the right ventricle . Moderate cardiomegaly is unchanged . The patient is status post interval thoracentesis on the right with a marked decrease in extent of right pleural effusion , with minimal residual fluid at the base . A moderate left pleural effusion on the left persists , with associated atelectasis . There is no pneumothorax .
    OUTPUT:
    
Marked decrease in right pleural effusion status post thoracentesis .