Chronic myocardial ischemia

Question 1

definition

Answer 1

ischemia lasting weeks, months, or years

Question 2

What can sublethal chronic ischemia cause?

Answer 2

cardiac myocytes hunker down metabolically, catabolize their contractile proteins, and revert to a primitive state limited to survival functions

Question 3

What does hibernating myocardium show under light microscopy and why?

Answer 3

vacuolization of myocyte cytoplasm

due to catabolism of contractile proteins

Question 4

vacuolization

Answer 4

clearing

Question 5

What is the light microscopy finding of vacuolization of myocyte cytoplasm due to catabolism of contractile proteins called?

Answer 5

myocytolysis

Question 6

What happens if adequate blood flow is restored?

Answer 6

function of chronically ischemic myocytes can return w/ regeneration of all normal cytoplasmic proteins

Return is GRADUAL

Question 7

When do collateral coronary arteries develop?

Answer 7

when chronic myocardial ischemia causes growth or enlargement of arteries into ischemic areas (if ischemia develops slowly enough)

Question 8

What is ischemic preconditioning?

Answer 8

brief episodes of myocardial ischemic insult may render insulted myocytes less vulnerable to infarction w/ subsequent episodes
due to induction of protective proteins

Question 9

Brief ischemia can…

Answer 9

provide ischemic preconditioning protection for subsequent ischemia

Question 10

Longer ischemia can…

Answer 10

stun myocytes…temporarily unable to work

Question 11

Chronic ischemia can..

Answer 11

make myocytes hibernate