Enzymes + Cardiac biochemistry

Question 1

What clinical approach should be done to detect the source of a raised ALP?

Answer 1

1. Check LFTs (due to metastasis)
2. Check Vit D (can increase ALP)

Question 2

What organs is ALP released from?

Answer 2

1. Biliary system (cholestasis)
2. Bone (Cancer, Fractures, Hyperparathyroidism, Vit D deficiency, other bone)
3. Placenta (3rd trimester pregnancy, germ cell tumours)
4. Intestine

Question 3

What orgnas is ALT released from?

Answer 3

1. Hepatic
2. Renal
3. Pancreatitis
4. MI

Question 4

What tissues is LDH released from?

Answer 4

Any cells relying on anaerobic metabolism

Question 5

What are differentials for increased serum amylase?

Answer 5

Question 6

What are differentials for elevated CK?

Answer 6

Usually Skeletal muscle pathology, but might be cardiac

Question 7

What are differentials of elevated Troponin I?

Answer 7

Usually cardiac-specific
(Cardiac specific Trop measured: cardiac myosite damage)

Question 8

What time post MI would Troponin be expected to be elevated?

Answer 8

Overall: 50% change in Troponin suggestive of Cardiac myocyte injury due to ACS

Elevated from around 2h
Peaks around 12h
Still elevated 5 days later

Question 9

When should troponin levels be measures post- potential cardiac event?

Answer 9

6h and
12h

Question 10

What is the half life and production time of BNP ?

Answer 10

Produced within 1h of cardiac stress
Half life 18mins

Therefore: measure NTproBNP (half life 3h)

Question 11

What might an incgrease in gamma-gt suggest?

Answer 11

Question 12

What is troponin?

Answer 12

cardiac and skeletal myocytes where it participates in muscle contraction