Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post CABG with sternal wires and mediastinal clips . The heart is mildly enlarged . There is a small left - sided effusion . There is dense retrocardiac opacity consistent with volume loss / infiltrate / effusion . There is pulmonary vascular redistribution .
    OUTPUT:
    
CHF . An underlying infectious infiltrate on the left can not be excluded .