Aortic Stenosis (AS)

Question 1

Definition of AS

Answer 1

• Obstruction of blood flow across the aortic valve due to pathological narrowing.

Question 2

Aetiology of AS

Answer 2

• Calcification of the aortic valve is the most common cause
• Other causes include:
  
  • Congenital bicuspid valves
  • Degeneration caused by rheumatic valve disease

Question 3

Signs and Symptoms of AS

Answer 3

• Ejection-systolic, high pitched murmur that radiates to the carotids andhas a crescendo-decrescendo character.
• Signs/symptoms include dyspnoea, chest pain, syncope, slow-rising pulse and a narrow pulse pressure.
• Risk factors include age >60 years, congenitally bicuspid valve, rheumatic heart disease, CKD.

Question 4

Pathophysiology of AS

Answer 4

• When valvular endocardium is damaged because of abnormal blood flow across the valve it initiates an inflammatory process like atherosclerosis, leading to deposition of calcium on the valve.
• Progressive calcium deposition limits aortic leaflet mobility and eventually produces stenosis.
• Leads to increased LV cavity pressure and so LV hypertrophy

Question 5

Investigation of AS

Answer 5

• Transthoracic echocardiogram (including Doppler)
  
  • Elevated aortic pressure gradient, measurement of valve area and left ventricular ejection function
• ECG
  
  • May demonstrate LVH and absent Q waves, AV block or BBB

Question 6

Treatment of AS

Answer 6

• Surgical candidate
  
  • Surgical valve replacement
  • Long-term anticoagulation
  • Long-term endocarditis antibiotic prophylaxis
• Surgical non-candidate
  
  • TAVI
  • Long-term anticoagulation
  • Long-term endocarditis antibiotic prophylaxis