Aetiology

Classification:

• true congenital aortic stenosis:
  • the stenosis is manifest from birth
  • there is a small hole in a domed valve
    
    
• calcification of congenitally deformed valve:
  • premature calcification of a bicuspid aortic valve is the commonest cause of aortic stenosis
  • it is usually asymptomatic during the first three decades of life during which it may be diagnosed after hearing an aortic ejection sound and a soft ejection murmur
  • symptoms may begin in fourth decade of life
  • rarely, the congenital deformity may be a unicuspid valve
    
    
• senile aortic stenosis:
  • aortic cusp sclerosis occurs when calcium deposition spreads form the hinge areas of three otherwise normal cusps causing stenosis
  • patients are usually elderly - in their 70's
    
    
• rheumatic fusion of the valve commissures and thickening of cusps:
  • usually accompanied by aortic regurgitation and mitral valve involvement
  • it accounts for about 10% of acquired aortic stenosis