Aortic Stenosis (33)

Question 1

What are the causes of aortic stenosis?

Answer 1

• Post-inflammatory scarring (rheumatic heart disease)
• Senile calcific aortic stenosis
• Calcification of congenitally deformed valve

Question 2

What are the causes of sudden death in aortic stenosis?

Answer 2

• MI
• Aortic dissection

Question 3

Why does weakness in the arm occur after aortic valve endocarditis?

Answer 3

Thromboembolism which leads to cerebrovascular stroke

Question 3

How does stenosis occur?

Answer 3

Lipid accumulation, inflammation, calcification → valve thickening and stenosis

Question 4

What is the pathophysiology of aortic stenosis?

Answer 4

• As the aortic valve progresses from sclerosis to stenosis, the left ventricle encounters chronic resistance to systolic ejection (↑ afterload) → thickening of the left ventricular wall (hypertrophy)
• Effects of high left ventricular afterload include decreased left ventricular myocardial elasticity and coronary blood flow and increased myocardial workload, oxygen consumption, and mortality.
• Late manifestations of LVH include a smaller left ventricular chamber size, which decreases preload and worsens systolic dysfunction. The result is insufficient stroke volume, cardiac output, and ejection fraction. Finally, backward transmission of increased left ventricular pressure to the lungs may cause pulmonary venous hypertension and reactive vasoconstriction of the pulmonary vasculature.

Question 5

Which coagulation system will not be affected by warfarin?

Answer 5

Intrinsic pathway

Question 6

What is a thrombus?

Answer 6

Thrombus is defined as solid material formed from the constituents of blood in flowing blood.

Question 7

What are the surgical options for valve replacement?

Answer 7

• Mechanical valve – a long-lasting valve made of durable materials
• Tissue valve (which may include human or animal donor tissue)
• Ross Procedure – “Borrowing” healthy valve and moving it into position of the damaged aortic valve
• TAVI/TAVR procedure – Transcatheter aortic valve replacement

Question 8

Why should a metallic valve be removed if a patient develops IE?

Answer 8

• The valve will be a septic focus
• The valve will be dehiscent

Question 9

What is the alternative option for aortic valve replacement?

Answer 9

Aortic valve balloon valvuloplasty – the valve is widened using a balloon

Question 10

What is the cause of microscopic branching hyphae on a removed metallic valve?

Answer 10

• Fungal infection:
  
  • Candida
  • Aspergillus
  • Microsporum
  • Trichophyton
  • Epidermophyton

Question 11

Compare Mechanical vs. tissue valve.

Answer 11