Enzymes and Cardiac Markers

Question 1

When may amylase be raised

Answer 1

Mainly acute pancreatitis (minimum 3x upper limit, normally 10x upper limit)

Renal insufficiency
Intestinal infarct/peritonitis
Cholecystitis
salpingitis
Ectopic pregnancy
Abdominal cancers

Question 2

When may lipase be raised

Answer 2

Acute pancreatitis - 3x upper limit

Renal insufficiency
Small bowel ischaemia/infarction
Sepsis
DKA
Cholecystitis

Question 3

What is Creatine Kinase used for and when may it be raised?

Answer 3

Marker of muscle damage

10xUL - MI, Duchenne
Other - Rhabdomyolysis, statin-related myopathy

Question 4

Main sources of Alkaline phosphatase

Answer 4

BLIP

Question 5

Physiologically raised Alkaline phosphatase

Answer 5

Pregnancy (3rd trimester)
Childhood (growth spurt)

Question 6

Pathologically raised Alkaline phosphatase

Answer 6

5xUL - bone (Paget’s, osteomalacia), Liver (cholestasis, cirrhosis)

less than 5xUL - bone (tumours, fractures, osteomyelitis), liver (infiltrative disease, hepatitis)

Question 7

Where is B-type natriuretic peptide released from?

Answer 7

Ventricles of the heart

Question 8

What does B-type natriuretic peptide respond to?

Answer 8

Ventricular stretch

Question 9

B-type natriuretic peptide actions

Answer 9

Systemic vasoconstriction
Sodium retention
Renal sympathetic activity

Question 10

B-type natriuretic peptide result interpretation

Answer 10

less than 100 - excludes HF with high specificty
greater than 400 - detects HF with high sensitivity

Can it be CKD?

Question 11

Why use N-terminal pro-B-type natriuretic peptide?

Answer 11

More sensitive than B-type natriuretic peptide with greater prognostic value

Question 12

What is troponin?

Answer 12

Protein found in contractile apparatus of cardiomyocytes
NOT AN ENZYME
Released during myocardial damage

Question 13

How to interpret troponin?

Answer 13

Measure at 6 hours and 12 hours post onset of chest pain
Stays elevated for 3-10 days after