Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP single view of the chest has been obtained with patient in semi-upright position . Analysis is performed in direct comparison with the next preceding similar study of ___ . Status post sternotomy , ___ mitral valve prosthesis in place , permanent left - sided pacer with dual intracavitary electrode system , all unchanged . On the right side , the evidence of pleural effusion has again decreased slightly in comparison with the next preceding study of ___ at which time a mild increase of pleural effusion was noted in comparison with an image obtained two days earlier . These variations illustrate difficulties to quantitate pleural effusions on single portable chest views . On the left side , the evidence of pleural effusion is more impressive as it obliterates totally the entire left - sided diaphragm and the density reaches up to the hilar area and beyond . Also noted is an increased amount of pleural density along the mediastinal structures reaching into the left - sided apical area . No pneumothorax is identified .
    OUTPUT:
    
Further increasing left - sided pleural effusion likely to compromise left side lung function severely . ___ was paged to transmit findings . He had already observed the findings with massive pleural effusion and a pleural tap is planned later this afternoon .