The single leaflet begins at the aortic root wall and extends across the annulus but doesn't contact the wall. What is this called?

The single leaflet begins at the aortic root wall and extends across the annulus but doesn't contact the wall. What is this called?

• A. Unicuspid AS
• B. Bicuspid AS
• C. Tricuspid AS
• D. Quadricuspid AS

Answer: (A)

Understanding how the number and arrangement of aortic valve cusps show up on imaging helps identify the valve type. In a unicuspid aortic valve, there is effectively a single leaflet that begins at the aortic root wall and extends across the annulus, forming a solitary opening that often does not contact the opposite wall. This production of a lone cusp across the annulus is characteristic and explains why the valve appears severely stenotic despite there being only one functional leaflet. By contrast, a bicuspid valve would display two leaflets (often with a raphe), a normal tricuspid valve has three leaflets, and a quadricuspid valve has four leaflets—all with distinct patterns of how the cusps meet the annulus.

Understanding how the number and arrangement of aortic valve cusps show up on imaging helps identify the valve type. In a unicuspid aortic valve, there is effectively a single leaflet that begins at the aortic root wall and extends across the annulus, forming a solitary opening that often does not contact the opposite wall. This production of a lone cusp across the annulus is characteristic and explains why the valve appears severely stenotic despite there being only one functional leaflet. By contrast, a bicuspid valve would display two leaflets (often with a raphe), a normal tricuspid valve has three leaflets, and a quadricuspid valve has four leaflets—all with distinct patterns of how the cusps meet the annulus.