Aortic Stenosis definition, incidence and prevalence.

Aortic Stenosis (AS)

Overview
-Aortic (aortic valve) Stenosis (abnormal narrowing of a passage) can be defined by restricted systolic opening of the valve leaflets with a mean transvalvular pressure gradient of at least 10 mm Hg
-The aortic valve does not open fully.
-Valve leaflets become coated with deposit. The deposits change the shape of the leaflets and reduce blood flow through the valve. The left ventricle has to work harder to make up for the reduced blood flow.
-May have no symptoms at all until late in the course of the disease.
-Diagnosis will be made based on the “heart murmur” and additional tests.

Incidence and Prevalence
-5 out of 10,000 people in US
-Common congenital cardiac defect (4 in 1000 live birth)
- AS caused by a congenital bicuspid aortic valve affects more men than women
-Later life calcific disease of a trileaflet valve affects both genders equally.
-80% of adults with symptomatic AS are male
-ppl >75 y/o, 3% have critical AS
-ppl <70y/o, 2% have AS

Mortality and Morbidity
-Sudden cardiac death: 3~5%
-Adult with AS: 9% mortality per year
-Incidence of sudden death after symptoms developed” 15~20% (survival duration <5 year)

Reference:
http://www.texasheartinstitute.org/HIC/Topics/Cond/vaortic.cfm
http://www.cardiologychannel.com/aorticstenosis/index.shtml
http://emedicine.medscape.com/article/757200-overview
http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/cardiology/aortic-valve-disease/