Aani CP: Enzymes & Cardiac Markers &LFTs

Question 1

GGT is a specific marker for which organ?

Answer 1

Liver

Question 2

What is the most commonly used marker of muscle damage?

Answer 2

Creatine Kinase (CK)

Question 3

When might a raised CK level be normal (physiological)?

Answer 3

In black people
Exercise (slight)
V. muscley people

Question 4

4 Pathological causes of raised CK?

Answer 4

• Duchenne Muscular Dystrophy
• Rhabdomyolysis
• MI
• Statin related myopathy

Question 5

4 organs in which high levels of ALP are found

Answer 5

1. Bone
2. Placenta
3. Liver
4. Intestine

Question 6

Physiological causes of raised ALP?

Answer 6

Pregnancy - 3rd trimester (placenta)
Growing Child (bone)

Question 7

When is amylase high?

Answer 7

Acute Pancreatitis

Mumps

Question 8

Pathological causes of VERY high ALP >5ULN (organ by organ)

Answer 8

1. Bone = Pagets, osteomalacia/rickets

2. Liver = Cholestasis, Cirrhosis

Question 9

Pathological causes of quite high ALP <5ULN (organ by organ)

Answer 9

1. Bone = Fractures, tumours, osteomyelitis

2. Liver = Hepatitis, infiltrative disease

Question 10

Which type of CK is released from the heart?

Answer 10

CK-MB (Clue: My Baby is in my heart)

Question 11

Which type of CK is released from skeletal muscles?

Answer 11

CK- MM

Question 12

What does calcitonin do?

Answer 12

Opposes the effects of PTH i.e. lowers serum calcium

Question 13

What is calcitonin a marker for?

Answer 13

Medullary thryroid carcinoma (because it is produced in the parafollicular cells of the thyroid)

Question 14

What would the ALP be in osteoporosis?

Answer 14

Normal. Unless they’ve had a fracture

Question 15

What is the unit of enzyme activity?

Answer 15

U/L

Question 16

Which liver enzyme cleaves statins?

Answer 16

CYP 3A4

Question 17

What is the diagnostic criteria for Acute MI?

Answer 17

1. Either rapid rise troponin and gradual fall OR
   Rapid rise and fall of CK MB

AND

2. One of the following:
   - Pathological Q waves on ECG
   - Ischaemic symptoms e.g. chest pain
   - ECG changes indicative of ischaemia
   - Coronary Artery Intervention

Question 18

Which cardiac enzyme is useful for diagnosing reinfarction?

Answer 18

CK MB
Re-infarction is when there is infarction followed by infarction again.
So you want to see a FRESH change so the most useful enzyme will be one that rises and falls quickly.
CK MB rises 6-12 hours and peaks at 24 hours - it then drops and normalises around 48-72 hours so it will be a good one to show re-infarction.

LDH stays risen for about a week
Troponin takes 10 days to normalise
These are useful for initial infarction but NOT re-infarction