X-Ray chest PA view showing features of severe pulmonary hypertension. There is mild cardiac enlargement with prominence of the right atrial contour (RA), which is extending more to the right than usual. Main pulmonary artery is prominent (MPA) and left pulmonary artery can be seen descending within the cardiac silhouette within the left cardiac border (starting behind the main pulmonary artery). Right pulmonary artery is also dilated (RPA). End on view of a few pulmonary arteries are also seen. Presence of end on view of multiple pulmonary arterial branches would suggest a significant left to right shunt as the cause of pulmonary hypertension. In Eisenmenger syndrome, right atrial enlargement along with features of pulmonary hypertension would indicate a pre-tricuspid shunt as the cause (atrial septal defect). In atrial septal defect with Eisenmenger syndrome, the pulmonary arterial pressures can reach supra systemic levels. Suprasystemic pulmonary arterial pressures do not occur in ventricular septal defect or patent ductus arteriosus as the large post tricuspid communication equalizes the pressures on both sides.