Cardiac Biomarkers in the Diagnosis of Ischaemic Heart Disease Flashcards
What are the most important cardiac markers
Troponin and BNP
What is troponin
It is uniquely expressed by the heart. It is involved in muscle contraction as it is attached to the protein tropomyosin and lies in actin filaments. Troponin is where the binding site for myosin on actin is.
What are the three types of troponin
I, C and T
What are the indications of increased levels of troponin
Increased risk of future cardiac events occurring.
What are the indications if you have both decreased cholesterol and troponin levels
Reduced risk of future cardiac events.
What are the indications if you have reduced cholesterol but troponin levels are the same
There is no change in the risk of future cardiac events.
What are the main drugs used in the treatment of heart disease
Statins
What are the risk factors for cardiovascular disease
- age
- gender
- smoking status
- high systolic blood pressure
- high total cholesterol
- low HDL cholesterol
- diabetes
What is high sensitivity C-reactive protein a biomarker for
Oxidative stress and inflammation
At what level does C-reactive protein indicate a high risk of CVD
More than 3mg/L.
What is C-reactive protein
An acute phase protein produced by the liver and adipose tissue.
What is the role of C-reactive protein
It assists in complement binding in the immune response and phagocytosis of damaged cells.
What is the role of C-reactive protein in atheroma formation
It is present in atherosclerotic lesions. it binds to LDL and assists macrophage uptake as well as enhancing local inflammation.
What are the possible causes of chest pain
MI, angina, pericarditis, pneumothorax, pulmonary embolism, gastric reflux, peptic ulcer disease, muscular or skeletal pain.
What type of cell is troponin released from
Cardiac troponins are released into the bloodstream from ischaemic cardiomyocytes.
What are the advantages of using cardiac troponin in diagnosis of acute MI
- it can detect smaller changes - it is more sensitive
- it is more specific to MI
- It remains elevated fro up to 2 weeks after an MI
What is type 1 MI
Spontaneous MI related to ischaemia due to a primary coronary event such a blockage of an artery.
What is type 2 MI
Mi secondary to ischaemia due to either increased oxygen demand or decreased oxygen supply (imbalance in supply and demand)
What is type 3 MI
Sudden unexpected cardiac death often with symptoms suggestive of myocardial ischaemia
What is type 4 MI
MI associated with PCI/stent thrombosis
What is type 5 MI
MI associated with CABG
What are the differences in troponin levels normally in men and women
Men naturally have higher cardiac troponin than women.
What is the normal concentration of troponin for a man
Below 34 ng/L
What is the normal concentration of troponin for a woman
Below 16 ng/L
What would be the issue if the troponin threshold for diagnosis of MI was the same for men and women
Less women within an abnormal range would be diagnosed with MI and so would not be treated, putting them at a huge disadvantage.
At what level of troponin can you definitely say the person has not had an MI and they can be sent home
Below 5 ng/L
What happens if the troponin level is above 5 ng/L
Another test is carried out after three hours to check troponin levels again before a diagnosis is made.
What stimulates the secretion of natriuretic peptides
Ventricular stretch due to increased blood volume and wall tension.
How is BNP produced
Prohormone is released in response to ventricular stretch and is cleaved to produce BNP.
What is the role of BNP
To regulate blood pressure, blood volume and sodium balance.
Where is ANP produced
The atria
Where is BNP produced
The brain and the ventricles
Where is CNP produced
The vascular endothelium
What level of BNP indicates heart failure
High
What investigation does BNP reduce the need to carry out
ECHO
