CVD Biochemistry (Zana)

Question 1

Acute MI symptoms

Answer 1

• symptoms of ischemia
• ECG changes (ST, LBB)
• ECG Q wave
• imaging evidence of myocardial ischaemia

Question 2

What does it mean when there is non-ST elevation and CK-MB/Troponin is normal and what does it mean when it is high?

Answer 2

when it is normal: USAP (unstable angina)

when it is high: NSTEMI (non-ST elevation MI)

Question 3

What is common pathophysiological pathway in acute MI and NSTEMI?

Answer 3

coronary artery plaque rupture, followed by series of events resulting in thrombosis formation

Question 4

Acute coronary syndrome is

Answer 4

Acute coronary syndrome is the term used to embrace ST segment elevation myocardial infarction (STEMI), as well as NSTEMI and unstable angina pectoris

Question 5

Troponins

Answer 5

Troponins are muscle-regulatory proteins present in skeletal and cardiac muscle.
Three troponins have been reported, namely troponin C (TnC), troponin I (TnI) and troponin T (TnT).

Question 6

Between which troponins is there a structural difference?

Answer 6

Between skeletal and cardiac forms of TnI and TnT

Question 7

Troponin ____ and _____ appear in the plasma 4–8 h or earlier with high-sensitivity troponin assays after symptoms of acute myocardial infarction, and are best measured 12 h after the start of chest pain

Answer 7

Troponin I and TnT

They are therefore not early markers of acute myocardial infarction, but they do stay elevated for about 7–10 days in plasma, which makes them useful in the late presentation of chest pain.

Question 8

In which nonischemic conditions are plasma troponins increased? (5)

Answer 8

• in subarachnoid haemorrhage (due to vasoactive peptide release affecting the myocardium)
• hypertension
• tachyarrhythmias, cardiac surgery, sepsi
• congestive cardiac failure
• pulmonary embolism and hypothyroidism

Question 9

Unlike ______ , _______________ have prognostic value after coronary thrombolysis therapy, with ___________ concentrations on admission correlating with 6-week mortality

Answer 9

CK-MB
Cardiac troponins
Troponin

Question 10

Myoglobin definition

Answer 10

• low molecular weight heme- containing protein found in skeletal and cardiac muscle

Question 11

When does myoglobin concentration rise?

Answer 11

• released from myocardium upon damage 2-4h after the onset of acute MI

Question 12

Is myoglobin cardiac specific?

Answer 12

No, it is also found in skeletal muscle and thus is less useful in diagnosis if not combined with other markers

Question 13

Cardiac enzymes

Answer 13

CK - plasma estimation of greatest value, but troponins are more important today

CK samples are taken at least 4h after onset of chest pain and then again after 4-6h

LDH, HBD and AST were used at some point, but today they are rarely used

Question 14

Prolonged CK plasma rise may suggest ______

Answer 14

cardiac ventricular aneurysm

Question 15

Second rise of plasma enzymes after their return to normal may indicate _______

Answer 15

extension of damage

Question 16

What happens with AST during MI? (3)

Answer 16

• similar change to CK
• rises significantly less
• even a small MI does cause some hepatic congestion due to right-side heart dysfunction

Question 17

Chronic heart failure (CHF) definition

Answer 17

Chronic heart failure can be defined as a clinical condition associated with symptoms and signs of left or right ventricular dysfunction.

Question 18

Signs and symptoms of CHF are (6)

Answer 18

dyspnea
fatigue

signs of fluid overload:
pulmonary crepitations
peripheral edema
raised jugular venous pressure

Question 19

3 major natriuretic peptides

Answer 19

ANP - atrial natriuretic peptide

BNP - brain natriuretic peptide

CNP - C-type natriuretic peptide

Question 20

ANP - atrial natriuretic peptide

Answer 20

is produced in the atria and is released upon increased atrial wall tension, such as occurs with increased intravascular volume.

Question 21

BNP - brain natriuretic peptide

Answer 21

is found in brain and cardiac ventricles and its concentration is increased in the plasma in cardiac failure and ventricular hypertrophy.

Question 22

CNP - C-type natriuretic peptide

Answer 22

C-type natriuretic peptide exists in a number of tissues, including the brain, kidney and endothelial cells.

Question 23

According to NICE guidelines ___________ and __________ may be useful markers of cardiac failure

Answer 23

plasma BNP
pro-BNP

Question 24

Plasma BNP has prognostic value in 2 conditions

Answer 24

• acute coronary syndrome
• cardiac failure

Question 25

What is released into the plasma upon thrombosis formation when fibrinogen is converted to fibrin?

Answer 25

D-dimers

Question 26

D-dimer is a useful marker of presence of _______ and useful in diagnosis of ________

Answer 26

thrombus
DVT

Question 27

Homocystenuria connection to thrombotic activity (4)

Answer 27

• recent studies show homocysteine is CVD risk factor
• deficiency of cystathionine b-synthase leads to thrombotic tendency
• raised homocysteine, raised risk for CVD
• can be elevated due to deficiency in vitamin B12, B6 and folate

Question 28

Plasma homocysteine concentrations above _______ µmol/L confer increased cardiovascular risk.

Answer 28

10 µmol/L