Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single AP view of the chest provided . Left chest wall pulse generator with continuous leads terminating in the right ventricle is unchanged . There is an opacity at the right lung base , which may be due to underpenetration . No pleural effusion or pneumothorax . Stable moderate cardiomegaly .
    OUTPUT:
    
1 . Opacity at the right lung base may be due to under penetration , however underlying opacity due to pneumonia can not be excluded . 2 . Moderate cardiomegaly is stable .