Aortic Stenosis

DEFINITION

Aortic Stenosis (AS) is the most common cause for obstruction of flow from he LV into the aorta_it is present in 2% of those>65 age and 4% of those > 85 age

AS is thickening of the aortic valve leaflets that cause turbulent flow through the valve and a murmur but no significant gradient; over time it can develop into AS

EPIDEMIOLOGY

1/Calcific/degenerative
        *Most common in U.S
        *Usually present in the 7th to 9th decades
        *Active biological process with bone formation in the Valve
       *Calcification leading to stenosis affects both trileaflet and biscupid valves
2/Bicuspid
        *in 1% to 2% of population (congenital lesion)
        *Usually present in the fifth to 8th decades
        *around 50% of patients needing AVR for AS have a bicuspid valve
        *More prone to endocarditis than trileaflet valve
        *Associated with aortopathies
3/Rheumatic
       *Most common cause worldwide
       *Usually present in the 3rd to 5th decades
       *Almost always accompanied by mitral valve disease