2DE examinations with good-quality images in 138 neonates<3 months corrected gestational age with PDA, and 50 normal neonates without PDA were selected. Measurements of LA, RA, and combined atrial volumes were performed, in addition to transductal diameters, left atrial to aortic dimension (LA:Ao), and left ventricular end-diastolic to aortic dimension ratios