Chem Path: Enzymes and cardiac markers

Question 1

What is KM

Answer 1

Substrate velocity at which the reaction velocity is 50% of the maximum

Question 2

During cell injury, which enzyme gets released first and which one gets released later?

Answer 2

Cytosolic first, sub-cellular next

Question 3

What do you do for unexplained ALP rise

Answer 3

1 Check LFTs to see GGT and ALT
2 Check Vit D
3 ALP isoenzymes via electrophoresis

Question 4

Why can ALP be raised

Answer 4

Pregnancy
Children in general
Cholestatic liver disease

Question 5

Why is GGT better than ASP in terms of liver function testing?

Answer 5

GGT is specific to the liver. ASP is also produced by the muscles

Question 6

Is ALP raised in osteoporisis

Answer 6

No

Question 7

What would you think when ALP and AST are both high?

Answer 7

Liver problem but can also be in myopathy or in those who exercise A LOT

Question 8

What indicates VERY HIGH ALT

Answer 8

Paracetamol overdose
Hepatitis
Ischaemia

Question 9

What can cause raised GGT other than liver causes

Answer 9

Normal cell turnover, alcoholics, rifampicin, phenytoin, phenobarbitone

Question 10

What can cause increased LDH

Answer 10

Lymphoma, haemolytic anaemia, germ cell tumour (especially testicular tumour), myositis,

Question 11

What has raised amylase

Answer 11

Acute pancreatitis, perforated duodenal ulcer

Question 12

What is macro amylase

Answer 12

Amylase bound to immunoglobulin. Often benign

Question 13

What causes creatinine kinase

Answer 13

Rhabdomylosis. myositis

Question 14

Why can you have muscle pain when taking statins

Answer 14

Statin related myopathy

Question 15

What is the pattern of cardiac enzyme increase during heart attack

Answer 15

Troponin rises first within 12 days and stays for 3-10 days

CK-MB next, total Ck next, AST next, finally LDH

Question 16

When someone comes in with chest pain, when do you check troponin?

Answer 16

On admission and 3 hours later. Look for 50% rise.

Question 17

What are the 2 ways you diagnose acute MI

Answer 17

1) (Rise and gradual fall of troponin OR rapid rise and fall of Ck MB) + one of these symptoms (Ischaemia, pathological q waves, ecg changes,)
2) Pathological findings of an acute MI