Bicuspid aortic valve is the presence of only two (rather than the normal three) valve cusps.
Bicuspid aortic valve is the most common congenital cardiovascular abnormality. It is present in 0.5 to 2 % of live births (1).
Patients with bicuspid aortic valve are predisposed to developing infective endocarditis, aortic regurgitation, and/or aortic stenosis. Bicuspid aortic valve can also be associated with dilation of the aortic root or ascending aorta and with coarctation of the aorta.
There is a genetic predilection for bicuspid aortic valves, with a 9% reported family prevalence, so first-degree relatives of patients with a bicuspid aortic valve should undergo screening echocardiography. Recognition of a bicuspid valve, even in a patient who has normal valve function, is important for purposes of follow-up because of the association of bicuspid valves with an aortopathy that results in progressive aortic root or ascending aortic dilation and aneurysm formation. The reported prevalence of this complication varies widely in different studies, but, in general, dilatation will occur in up to 56% of those aged < 30 years (2).
General references
1. Freeze SL, Landis BJ, Ware SM, Helm BM: Bicuspid aortic valve: a review with recommendations for genetic counseling. J Genet Couns 25(6):1171–1178, 2016.
2. Tadros TM, Klein MD, Shapira OM: Ascending aortic dilatation associated with bicuspid aortic valve: pathophysiology, molecular biology, and clinical implications. Circulation 119(6):880–890, 2009. doi: 10.1161/CIRCULATIONAHA.108.795401
Symptoms and Signs of Bicuspid Aortic Valve
Children with bicuspid aortic valve may be asymptomatic if there is little or no valve dysfunction. Symptoms depend on the type of complication and can include fever in infective endocarditis or dyspnea, fatigue, syncope, palpitations, and exercise intolerance due to valvular regurgitation or stenosis.
Examination reveals an early systolic click, a systolic ejection murmur and, if aortic regurgitation is present, a diastolic decrescendo murmur.
Diagnosis of Bicuspid Aortic Valve
Physical examination
Echocardiography
Diagnosis is by physical examination findings and echocardiography. Physical examination usually reveals a prominent early systolic ejection sound (click) at the apex and base of the heart. This finding is often best heard with the patient sitting; the examiner listens at the apex for a click just after the first heart sound (S1), simulating a prominent split of S1. There may be a basal systolic murmur due to aortic stenosis or a high-pitched diastolic murmur if aortic regurgitation is present.
Echocardiography shows the characteristic finding of fusion of two of the three aortic valve leaflets. Fusion of the right coronary and left coronary leaflets is the most common morphology. Children with fusion of the right coronary and noncoronary leaflets are more likely to have progression of valve dysfunction and to require intervention during childhood.
Treatment of Bicuspid Aortic Valve
Balloon dilation or surgical repair
Treatment of bicuspid aortic valve is indicated if severe valve dysfunction develops and if symptoms occur. Treatment consists of balloon dilation or surgical repair of stenotic valves. Regurgitant valves are treated with surgery.
Ascending aorta or root replacement may be indicated if there is severe or progressive enlargement of those structures.
More Information
The following English-language resource may be useful. Please note that The Manual is not responsible for the content of this resource.
American Heart Association: Common Heart Defects: Provides overview of common congenital heart defects for parents and caregivers
