31&32: Cardiac Function 1

Question 1

What is considered a normal EF?

Answer 1

> 50-55%

Question 2

What are the risk factors for HFpEF?

Answer 2

• Older
• Female
• Hypertensive
• Diabetic
• Atrial fibrillation
• Chronic kidney disease

Question 3

What factors influence cardiac relaxation?

Answer 3

• Release of tension when Ca dissociates from TnC
  Titin recoil from compression
• Cardiac afterload

Question 4

What factors influence cardiac compliance?

Answer 4

• AV pressure gradient

- Chamber stiffness (collagen, titin, geometry)

Question 5

How do you calculate:

• Pulse pressure?
• MAP?

Answer 5

PP = Ps - Pd
MAP = Pd + 1/3PP

Question 6

What are treatment options for patients with diastolic heart failure?

Answer 6

• Reduce congestive state (diuretics)
• Reduce HR (prolong filling time) - beta blockers, ‘treat’ AF if present
• Control hypertension
• Reduce/reverse remodelling (ACE-Is, AII blockers, spironolactone)

Question 7

What is notching on an ECG indicative of?

Answer 7

Bundle branch block

Question 8

Why might patients with heart failure develop a bundle branch block?

Answer 8

• CHF causes inflammatory/fibrotic changes in the myocardium and conduction system
• Can lead to discoordinated contraction and relaxation

Question 9

When is CRT indicated?

• QRS
• LVEF
• Therapy

Answer 9

QRS > 150ms
LVEF < 30-40%
Already optical medical therapy but still experiencing symptoms