What is the etiology of aortic stenosis?

What is the etiology of aortic stenosis?

AS may be congenital or acquired. In adults, a congeni-tally bicuspid valve may become calcified and stenotic. Senile calcification of a tri-leaflet aortic valve is common in patients over 70 years of age. Rheumatic AS is almost always associated with rheumatic mitral valve disease. This etiology is becoming less common in developed countries because of the widespread use of antibiotic therapy.