A 2-month-old boy is found unresponsive in his crib. He had previously been well and had a normal physical examination at his 2-month visit approximately 1 week earlier. An autopsy is performed to determine the cause of death. The pathologist concludes that the infant likely died of sudden infant death syndrome. The autopsy also shows an incidental finding of bicuspid aortic valve. If this patient had survived, he would have been at greatest risk for which of the following events?

Question

A 2-month-old boy is found unresponsive in his crib.  He had previously been well and had a normal physical examination at his 2-month visit approximately 1 week earlier.  An autopsy is performed to determine the cause of death.  The pathologist concludes that the infant likely died of sudden infant death syndrome.  The autopsy also shows an incidental finding of bicuspid aortic valve.  If this patient had survived, he would have been at greatest risk for which of the following events?

Quizplus · Accepted Answer

11ec160b_3a80_49c9_9249_59aebc27a4fe_MD0001_00 Bicuspid aortic valves (right and left aortic cusp fusion) occur in approximately 1%-2% of live births, making it one of the most common congenital heart defects. The abnormally shaped valve experiences increased hemodynamic stress, which accelerates the normal aging process and causes premature atherosclerosis and calcification of the aortic valve. These deposits begin accumulating as early as adolescence and lead to aortic stenosis in >50% of affected patients. Symptomatic aortic stenosis develops on average around age 50 (10 years earlier than the average onset of senile calcific aortic stenosis in patients with normal aortic valves). (Choice A) Patients with bicuspid aortic valves have a higher risk of aortic dissection. However, the absolute risk of aortic dissection is still <1%. As with other complications of bicuspid aortic valves, the risk increases with advancing age. (Choice C) Atrial fibrillation has not been associated with bicuspid aortic valves. (Choice D) Patients with bicuspid aortic valves are at increased risk for infective endocarditis. The risk is 2%-3% and rises with age due to increasingly turbulent blood flow across the abnormal valve. (Choice E) In early childhood, isolated bicuspid aortic valves usually are asymptomatic, without any hemodynamically significant degree of aortic outflow tract obstruction or murmurs. In contrast, congenital aortic stenosis usually produces a systolic murmur as a result of severe subvalvular, valvular, or supravalvular anatomic defects. (Choice F) The most common cause of ventricular fibrillation at age <30 is hypertrophic cardiomyopathy. This condition is not associated with bicuspid aortic valves. Educational objective: Aortic stenosis is the most common complication of bicuspid aortic valves. Patients with bicuspid aortic valves develop clinically significant aortic stenosis on average around age 50. In comparison, senile calcific stenosis of normal aortic valves generally becomes symptomatic age >65.

A 2-Month-Old Boy Is Found Unresponsive in His Crib