A 30 year old man with an undiagnosed cardiac anomaly has been unable to do strenuous exercise throughout his life. Auscultation demonstrates an immediate diastolic murmur, which has been be present since childhood. The patient has never been cyanotic. Which of the following disorders would most likely cause the patient's findings?

solated bicuspid aoic valve is a very common congenital anomaly, which may be completely asymptomatic or may cause modest noncyanotic obstruction related to stenosis. It is associated with an immediate diastolic murmur, related to some degree of aoic insufficiency that is often recognized in early childhood. Surgical correction of even mild to moderate stenosis or insufficiency is now recommended to prevent long-term damage to the hea muscle. The common pattern of transposition of the great vessels produces early cyanosis. Uncorrected patent ductus aeriosus produces a continuous ("machinery") murmur and late cyanosis. Tricuspid atresia , which is usually accompanied by an atrial septal defect, produces early cyanosis. Ref: Elefteriades J.A., Olin J.W., Halperin J.L. (2011). Chapter 106. Diseases of the Aoa. In V. Fuster, R.A. Walsh, R.A. Harrington (Eds), Hurst's The Hea, 13e.