“…Aorta-to-Pulmonary Artery Fistulas Aorta-to-pulmonary artery fistulas, often systemic-to-pulmonary and left-to-right shunts (Table), can be congenital (ie, PDA) or can result from a dissecting aneurysm (25)(26)(27)(28), Marfan syndrome (26), trauma or surgery (29)(30)(31), severe aortic stenosis (32,33), inflammatory aortitis (eg, giant cell arteritis) (34), and infection (eg, endocarditis, syphilis) (35)(36)(37). When acquired, they usually manifest acutely as a new continuous murmur in the setting of respiratory and cardiac failure.…”