Laboratory Investigation of Cardiac Disease Flashcards
- List 5 biochemical tests used in clinical medicine?
- Screening ( subclinical conditions that are not recognisable in clinical findings)
- Diagnosis (abnormal vs normal)
- Monitoring ( course of disease)
- Clinical management (treatment/response)
- Prognosis (risk stratification - classification into group depending on risk levels)
- What is a biomarker?
A substance which allows identification of the disease and measure of treatment effectiveness
- What are two analytical characteristics of an ideal biomarker?
- Measurable by cost-effective method and simple to perform.
- Rapid turnaround time with sufficient precision & accuracy.
- What are five clinical characteristics of an ideal biomarker?
- Early detection of disease and the ability to improve patient outcome
- Sensitivity vs specificity
- Validated decision limits
- Selection of therapy
- Risk stratification and Prognostic value (information about overall likely outcome of disease).
- Cardiovascular disease is an umbrella term for other lil diseases- give some examples of what diseases these would be?
• coronary heart disease (CHD), cerebrovascular disease, peripheral arterial disease, rheumatic and congenital heart diseases, venous thromboembolism and lymphatic disease.
- What % of deaths are caused by cardiovascular disease?
1/4
- Fill in the blank”
Every * minutes , someone dies from cardiovascular disease”
8
- What is the total healthcare cost of cardiovascular disease?
9 Billion
- Coronary heart diseases causes the most deaths in men and women , how?
Myocardial Infarction
Heart failure
- How does an atheromatous plaque develop?
- Foam Cells ( macrophages) localise to fatty deposits on blood vessels wall and infiltrate
- Lipids accumulate forming lipid cores , –> surface defects, thrombosis and sometimes haemorrhage
- What % of the age groups below have a risk of getting significant coronary atherosclerosis (build-up of plaques):
<20 year olds
20-29 year olds
30-39 year olds
20% in <20 year olds,
50% in 20-29 year olds and
up to 65% in 30-39 year olds.
- Describe the initiation of Atherosclerosis?
LDL penetrates the endothelium–>oxidative modification—> releases pro inflammatory lipids–> surface now expresses adhesion molecules –>surface monocytes adhere to–>Monocytes then enter the intima and respond to the cytokines–>M-CSF -> monocytes = macrophages–>upregulate expression of surface receptors–> release of proinflammatory mediators–> Receptors mediate the uptake of oxidised LDL–>cholesterol accumulation in the cell which then develops into a foam cell.
- What does M-CSF stand for?
macrophage colony stimulating factor - cytokine
- What is the main consequence of Coronary Thrombosis?
Ischaemia (decreased blood flow due to plaque build-up in the coronary arteries) can become necrosis (dead tissue). This can cause myocardial infarction.
- Explain the whole process of atherosclerosis in simple terms?
- Irritant (LDL, Toxins)
- Irritant disrupts endothelium
- Cholesterol build up (fatty streak) in damaged wall
- LDL oxidised
- Sends signals which cause monocytes to arrive
- M-CSF converts monocytes to macrophages
- Macrophages try to engulf LDL, become foam cells and die, release cytokines
- Smooth muscle cells form fibrous cap around plaque and release calcium (makes plaque hard)
- How can a plaque rupture lead to myocardial infarction?
o A plaque with a fibrous cap (muscle cells, foam cells, collagen/elastin etc) causes angina.
o When the cap ruptures and LDL is released, it causes acute coronary syndromes.
o A blood clot forms around the cap rupture, this blocks the artery and causes heart attack.
- Why is it important to define the type of ischaemic heart disease?
oIt is important to differentiate between stable angina and acute myocardial infarction because this determines the treatment, prognosis and management needed.
- What are some causes of chest pain?
o Broken ribs, collapsed lungs or ‘pulled’ muscles.
o Nerve infection (shingles) or other infections.
o Pericarditis (inflammation of the pericardium) or blood clot in the lungs (PE).
o Heart burn (hernia) or angina or myocardial infarction.
o Areas of radiation pain: neck, jaw, upper abdomen, shoulders or arms.
- What kind of assessments would you do for a patient with Ischaemia heart disease?
Medical history, Risk factors, Presenting signs/symptoms, ECG, Imaging/Scans and Biomarkers.
- What can biochemical markers of cardiac damage contribute to?
o Rule in/out an acute MI o Confirm an old MI o Help to define therapy and monitor success of therapy o Diagnosis of heart failure o Risk stratification of death
- What does irreversible myocardial injury require?
Irreversible injury typically requires 30 minutes of ischaemia.
22.How long does it take after damage for 80% of cardiac cells to die ? How about 100% of cells?
o High risk that 80% of cardiac cells die within 3 hours and almost 100% by 6 hours.
- During myocardial injury you may have cellular content leak out through membrane . What does this depend on?
Size
Solubility