ENZYMES AND ISOENZYMES OF ACUTE MI

Question 1

creatine kinase structure?

Answer 1

dimer

Question 2

isoenzymes?

Answer 2

MM (CK3)
MB (CK2)
BB (CK1)

Question 3

mm (CK3) is found where?

Answer 3

skeletal muscle(majority), cardiac muscle

Question 4

qMB (CK2) is found where?

Answer 4

cardiac muscle, small amounts in skeletal muscle

Question 5

BB (CK1) is found where?

Answer 5

brain, prostate, smooth muscle

Question 6

heart consists of how much MM and MB?

Answer 6

60/40

Question 7

when is CK-MB elevated?
peaks? persist?

what is key?

Answer 7

4-8 hours after MI
12-24 hours
72 hours

serial testing

Question 8

what enzyme is used for interpretation of the following:

MI
Muscular dystrophy
exercise
IM injections
Acute psychotic reactions
crush injury

Answer 8

total CK

Question 9

what enzyme is used for interpretation of the following:

acute MI
severe angina
open heart surgery
muscular dystrophy 
skeletal muscle injury

Answer 9

CK-MB (CK2

Question 10

this marker is faster, more specific than CK-MB (only found in the heart) and not in the serum of healthy individual

Answer 10

cardiac troponins

Question 11

these cardiac troponin form a complex of protein which regular Ca2+ mediated interaction of actin and myosin in cardiac muscle

Answer 11

T & I

Question 12

this cardiac troponin is found in the serum within 4 hours of AMI

reaches 100% sensitivity 6-8 hours after infarction

remains elevated 10-14 days

can be elevated in patients with angina at rest-increased risk developing AMI

Answer 12

cardiac troponin T

Question 13

this cardiac troponin appears in the serum 4 hours after onset of chest pain

sensitivity 50% at 4 hours
sensitivity 97% at 6 hours
peak levels at 8-12 hours
persists for 5-7 days

Answer 13

cardiac troponin I

Question 14

this cardiac troponin is elevated within 2 hours of AMI
-rapid renal clearance

also low specificity

Answer 14

myoglobin