enzymes and cardiac markers

Question 1

in what condition would you see high serum amylase?

Answer 1

acute pancreatitis
parotitis (mumps)

(because amylase found in pancreas & salivary gland)

Question 2

what is macro-amylase and the issue with it

Answer 2

-amylase bound to globulin (so bigger size)
-can be misinterpreted as high amylase

Question 3

in what condition would you see high serum lipase (>3x ULN)

Answer 3

acute pancreatitis

Question 4

what is the benefit of serum lipase in pancreatitis

Answer 4

more specific than amylase

Question 5

what is CK a marker of

Answer 5

muscle damage

Question 6

where are the different types of CK found

Answer 6

CK-MM = skeletal muscle
CK1&2 = cardiac muscles

Question 7

when can CK be raised physiologically

Answer 7

afro-carribean people(<5xULN)

Question 8

when can CK be raised pathologically

Answer 8

duchenne muscular dystrophy
MI
rhabdo
statin related myopathy

Question 9

when is CK better than troponin for MI?

Answer 9

short half life so better in reinfarction as trop can stay high for days

Question 10

what liver enzyme is high in MI

Answer 10

AST
(can be found in cardiac tissue)

Question 11

how can you differentiate between bone or liver related ALP rise

Answer 11

liver ALP rise would have a rise in GGT too

or electrophoresis, or bone specific ALP assay

Question 12

physiological causes of raised ALP?

Answer 12

pregnancy (3rd trimester)
childhood (growth spurt)

Question 13

causes of high ALP mnemonic?

Answer 13

BLIP

bone
liver
intestine
pancreas

Question 14

causes of high ALP >5x ULN

Answer 14

-Bone (Pagets, osteomalacia)
-Liver (cholestasis, cirrhosis)

Question 15

causes of high ALP <5x ULN

Answer 15

-Bone (tumours, fractures, osteomyelitis)
-liver (infiltrative disease, hepatitis)

Question 16

where is b-type natriuretic peptide (BNP) released from

Answer 16

mainly ventricles of the heart in response to ventricular stretch

Question 17

what do BNP levels tell us

Answer 17

<100 = exclude heart failure
>400 = sensitive for heart failure

Question 18

what may confound the interpretation of BNP levels

Answer 18

CKD

Question 19

what is NT-proBNP benefit?

Answer 19

more sensitive than BNP and greater prognostic value for heart failure

Question 20

what is troponin

Answer 20

a protein (not an enzyme) that forms part of contractile apparatus of cardiomyocytes

Question 21

when is troponin released and at what time should it be measured

Answer 21

after MI
-measure at 6hrs and 12hrs post-chest pain onset
-only rises 4hrs after MI
-remains elevated for 3-10 days
-also raised in other cardiac conditions

Question 22

what does international unit measure (IU)

Answer 22

enzyme activity

Question 23

difference between CK ad LDH

Answer 23

CK is quiCK, LDH is sLow

Question 24

what scan for neuroendocrine tumours like insulinomas, gastrinomas

Answer 24

gallium 68 dotate

(dotate binds to somatostatin receptors in NETs)

Question 25

what scan for abdominal mets

Answer 25

FDG-PET

(FDG is radiolabelled glucose taken up by metabolically active tumour cells)

Question 26

what scan for parathyroid disease

Answer 26

Tec99-sestamibi

(sestamibi taken up by PTH tissue)

Question 27

what scan for phaeochromocytomas

Answer 27

MIBG

(detects adrenergic neurotransmitters)

Question 28

what scan for thyroid disease

Answer 28

Tec99-pertechnecate

Technecate = thyroid

Question 29

what scan for bone mets & pagets

Answer 29

Tec99-bisphosphonate

(remember bisphosphonates treats hypercalcaemia cos of mets)