Bicuspid aortic valve
A bicuspid aortic valve (BAV) refers to a spectrum of deformed aortic valves with two functional leaflets or cusps which are often unequal in size.
They are most often congenital while an acquired bicuspid valve occurs when there is fibrous fusion between the right and left cusps of a pre-existing trileaflet aortic valve.
A congenitial biscuspid aortic valve is considered to be one of the most common causes of isolated aortic stenosis 4. It is considered a major cause of aortic valve disease in young adults.
The estimated incidence of a congenital bicuspid valve in the general population is thought to be ~ 2% . They may be more common in males.
BAV refers to a spectrum of deformed aortic valves with two functional leaflets or cusps which are often unequal in size. Only two cusps, commissures and sinuses are seen in the "pure" BAV subtype. However, usually there are three cusps associated with underdevelopment of a commissure and fusion of two adjacent cusps to form a raphe in the more common form of BAV7.
- autosomal dominant polycystic kidney disease
- coarctation of the aorta: ~70% (range 50-85%) of coarcations are thought to associated with bicuspid aortic valves 2
The usefulness of plain film in the detection of a bicuspid valve is considered to be rather poor. Occasionally the presence of a single calcified raphe at the expected site of the bicuspid valve may suggest a biscuspid valve 4.
While echocardiography is the standard diagnostic procedure for the evaluation of patients with valvular disease, differentiation of bicuspid valve from other types of calcific aortic stenosis can sometimes be difficult 4-5.
At the time of initial writing, an echocardiogram for the detection of a bicuspid aortic valve is thought to carry 6
- sensitivity: 76 %
- specificity: 60 %
- positive predictive value: 68 %
- negative predictive value: 95 %
At the time of writing, CT has much higher reported detection rate for bicuspid valves and include 6
- sensitivity : 94 %
- specificity : 100 %
- positive predictive value : 100 %
- nagative predictive value : 97 %
Characteristic “fish-mouth” shape of the open valve in systole is noted on ECG gated cardiac CT 7.
Recognized complications include