<prompt> Answer this question truthfullyWhat can be observed on a chest X-ray of an individual with atrioventricular septal defect?  <response>: <reason> Chest x ray in atriovenrticular defect showsProminent pulmonary vascular markings Cardiac enlargement, especially enlargement of the right atrium RA and right ventricle RVChest x ray below shows cardiomegaly with increased pulmonary vascular markings. 