Reperfused MI...Characteristic Microscopic Pathology Findings

Question 1

What findings immediately follow reperfusion?

Beginning of Acute phase

Answer 1

contraction band necrosis and hemorrhage

coagulation necrosis (especially in center of big infarct)
followed by neutrophilic infiltration

Question 2

What findings immediately follow reperfusion?

Beginning of Acute phase

Answer 2

contraction band necrosis and hemorrhage

coagulation necrosis (especially in center of big infarct)
followed by neutrophilic infiltration

Question 3

When is coagulative necrosis first visible?

Answer 3

2 hours following reperfusion

Question 4

no-reflow phenomenon

Answer 4

reversal of coronary obstruction by angioplasty or other means fails to restore blood flow into myocardium injured

Question 5

What can no-reflow phenomenon be attributed to?

Answer 5

capillary endothelial swelling
capillary plugging by neutrophils
microthrombosis
microembolism

Question 6

what can the hemorrhage caused by reperfusion be attributed to?

Answer 6

microvascular injury

Question 7

What happens if microvascular flow is restored?

Answer 7

edema and neutrophilic infiltration throughout reperfused infarct

while myocytolysis occurs in viable myocytes around infarct

Question 8

infiltration by macrophages

Answer 8

happens sooner and heavier than in unreperfused infarct…sometimes arrive by day 2

Question 9

Fibroblasts

Answer 9

also may arrive sooner, as early as day 3

Question 10

Early Subacute phase

Answer 10

Days 4-10

lymphocytes, sometimes eosinophils and plasma cells are present

formation of granulation tissue and then collagen

Reperfused infarct looks older than unreperfused infarct

Question 11

Late Subacute phase

Answer 11

Days 11-end

Question 12

with reperfusion, healing of large infarct can be…

Answer 12

accelerated from 12 to 7 wks

Question 13

with reperfusion, healing of small infarct can be..

Answer 13

done within 2 wks

Question 14

Reperfusion acclelerates…

Answer 14

healing by about 40% on average

Question 15

Patches of preserved myocardium usually interspersed with…

Answer 15

scar

Question 16

More of scar is commonly ____ rather than ___

Answer 16

interstitial rather than confluent

Question 17

Reperfusion injury

Answer 17

damage of tissue when blood supply is restored after a period of ischemia

can happen in any organ

Question 18

Examples of reperfusion injury

Answer 18

hemorrhage

no-reflow phenomenon

Question 19

MOA of reperfusion injury

Answer 19

cell membranes (already abnormally permeable b/c of ischemia) may allow excess calcium into cells w/ reperfusion

O2 brought in by restored flow can give rise to injurious oxygen-derived free radicals and ROS

restored flow can bring overzealous inflammatory cells

Question 20

interspersing of preserved mocardium with scar may…

Answer 20

make re-entrant ventricular cardiac arrhythmias more common b/c creates more irregular and circuitous routs for cardiac rhythm conduction

Question 21

When is coagulative necrosis first visible?

Answer 21

2 hours following reperfusion

Question 22

no-reflow phenomenon

Answer 22

reversal of coronary obstruction by angioplasty or other means fails to restore blood flow into myocardium injured

Question 23

What can no-reflow phenomenon be attributed to?

Answer 23

capillary endothelial swelling
capillary plugging by neutrophils
microthrombosis
microembolism

Question 24

what can the hemorrhage caused by reperfusion be attributed to?

Answer 24

microvascular injury

Question 25

What happens if microvascular flow is restored?

Answer 25

edema and neutrophilic infiltration throughout reperfused infarct

while myocytolysis occurs in viable myocytes around infarct

Question 26

infiltration by macrophages

Answer 26

happens sooner and heavier than in unreperfused infarct…sometimes arrive by day 2

Question 27

Fibroblasts

Answer 27

also may arrive sooner, as early as day 3

Question 28

Early Subacute phase

Answer 28

Days 4-10

lymphocytes, sometimes eosinophils and plasma cells are present

formation of granulation tissue and then collagen

Reperfused infarct looks older than unreperfused infarct

Question 29

Late Subacute phase

Answer 29

Days 11-end

Question 30

with reperfusion, healing of large infarct can be…

Answer 30

accelerated from 12 to 7 wks

Question 31

with reperfusion, healing of small infarct can be..

Answer 31

done within 2 wks

Question 32

Reperfusion acclelerates…

Answer 32

healing by about 40% on average

Question 33

Patches of preserved myocardium usually interspersed with…

Answer 33

scar

Question 34

More of scar is commonly ____ rather than ___

Answer 34

interstitial rather than confluent

Question 35

Reperfusion injury

Answer 35

damage of tissue when blood supply is restored after a period of ischemia

can happen in any organ

Question 36

Examples of reperfusion injury

Answer 36

hemorrhage

no-reflow phenomenon

Question 37

MOA of reperfusion injury

Answer 37

cell membranes (already abnormally permeable b/c of ischemia) may allow excess calcium into cells w/ reperfusion

O2 brought in by restored flow can give rise to injurious oxygen-derived free radicals and ROS

restored flow can bring overzealous inflammatory cells

Question 38

interspersing of preserved mocardium with scar may…

Answer 38

make re-entrant ventricular cardiac arrhythmias more common b/c creates more irregular and circuitous routs for cardiac rhythm conduction