Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single frontal portable radiograph of the chest was acquired . There is re-demonstration of a left - sided pacemaker with biventricular leads . Midline sternotomy wires are again noted , with surgical clips suggestive of prior CABG . An abandoned right - sided pacer lead is again noted . Heterogeneous left lower lung opacities are slightly increased compared to the prior study from ___ , likely atelectasis . There is minimal right basilar atelectasis . Moderate - to - severe cardiomegaly is not significantly changed . There is mild pulmonary vascular congestion . The mediastinal contours are not significantly changed . There are no definite pleural effusions . No pneumothorax is seen .
    OUTPUT:
    
1 . Slight increase in heterogeneous left lower lung opacities , likely atelectasis . 2 . Mild pulmonary vascular congestion in the setting of marked enlargement of the cardiac silhoutte is suggestive of a pericardial effusion versus cardiomyopathy .