Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette is enlarged but stable in size . Main pulmonary artery is prominent as well as the right atrial contour . Lungs are clear , and there are no pleural effusions or concerning skeletal findings .
    OUTPUT:
    
Persistent cardiomegaly . Enlarged right atrium in keeping with history of tricuspid regurgitation . Enlarged main pulmonary artery contour raising the possibility of pulmonary arterial hypertension . By report , borderline pulmonary arterial systolic hypertension was evident at the time of the patient 's last echocardiogram ___ .