Cardiovascular Disease Flashcards
What is atherosclerosis?
When fatty deposits block an artery directly
Describe the sequence of atherosclerosis
1 endothelium becomes damaged or dysfunctional
2 the inner lining of artery is breached and there is an inflammatory response
3 white blood cells leave the blood vessel + move into wall of artery where they accumulate cholesterol
4 a fatty deposit builds up called an atheroma
5 calcium salts and fibrous tissue build up site resulting in a swell called a plaque
6 plague is hard so artery loses some of its elasticity
7 plaque also causes lumen of artery to narrow, makes it difficult for heart to pump blood + increases blood pressure
What are the stages in the clotting cascade?
1 Platelets and damaged tissue release the protein thromboplastib
2 Thromboplastin activates an enzyme catalysing conversion of protein prothrombin to thrombin (calcium ions, vitamin K must be present)
3 Thrombin catalysed conversion of the soluble protein fibrinogen to the insoluble fibrin
4 A mesh of fibrin forms, trapping more platelets and RBCs, forming a clot
What is cardiovascular disease?
Diseases of the heart and circulation
What are features of a well designed study?
- clear stated aim/hypothesis
- design appropriate for question
- symptoms of people w/ disease are clearly defined
- use correct measurement method for DV and repeating
- timescale of study is suitable for exposure to + development of disease
What are the two types of studies for identifying risk factors ?
Cohort - following a large group of people over time to see who does and doesn’t develop the disease (prospective)
Case-controlled - comparing people with the disease to those without (retrospective)
Identify some risk factors for CVD + why
Low-density lipoproteins (high blood cholesterol), smoking (carbon monoxide increases deposition of cholesterol in atheroma formation), salt (kidneys retain too much water = higher fluid content = higher blood pressure), exercise (increases HDLs and lowers LDLs), antioxidants, obesity, alcohol, age (arteries become less elastic), sex (women naturally have higher HDL levels), genetics, stress
Why is obesity a risk factor for CVD?
- higher blood sugar = higher blood pressure, makes blood more viscous
- Excess weight = high blood pressure + high cholesterol
- increases risk of CHD even without other factors
Why is smoking a risk factor for CVD?
- contains free radicals
- contains carcinogens —> cancer causing
- contains carbon monoxide —> binds to haemoglobin, reducing oxygen delivered to tissue and increases cholesterol deposition in atherosclerosis
- nicotine stimulates adrenaline —> increases heart rate, also increases stickiness of platelets
-decreases levels of antioxidants, damages artery lining
What are main treatments for high blood pressure?
Antihypertensives = drugs treating high blood pressure
- Diuretics - help reduce fluid buildup in the body
- help kidneys remove salt + water through urine
- lowers amnt of fluid flowing through veins + arteries
Beta blockers
- block the effect of adrenaline
- causes heart to beat slower and with less force
ACE inhibitors
-reduce synthesis of the hormone angiotensin II
- which causes vasoconstriction of blood vessels
Calcium channel blockers
- blocks calcium channels in artery lining, prevents them contracting
What are treatments to reduce blood cholesterol?
- Diet low in saturated fats and cholesterol
- Statins = medication which inhibits an enzyme involved in LDL production in the liver
- Anticoagulants & platelet inhibitors = reduce blood clotting
e.g. aspirin + clopidogrel reduce stickiness of platelets and thus likelihood of clot formation
e.g. warfarin - interferes with vitamin K production and affects synthesis of clotting
Why might perception of risk be overestimated or underestimated?
-
Overestimated when
~ unfamiliar with event
~ overexposure to info
~ personal experience
~ severe consequences
~ not under their control -
Underestimated when:
~ harm is non immediate
~ lack of info
~ enjoyment of an activity
~ unfamiliar with event
Differentiate between correlation and causation
Correlation —> change in one variable occurs at same time as another
Causation —> one variable causes change in another
= important to differentiate as third variable could be causing a change
Describe two methods for identifying obesity
Waist-to-hip ratio
Circumference of waist/ Circumference of hips in cm
- for women this should be less than 0.86; for men should be less than 1
Body mass index (BMI)
Mass (kg) / height^2 (m^2)
- 18.5 - 24.9 is considered normal
- BMI of over 30 is considered obese
Outline benefits and risks of different CVD treatments
Antihypertensives
Benefits: reduce blood pressure, can monitor BP at home, can combine multiple drugs to increase efficacy
Risks: Side effects like headaches, drowsiness, heart palpitations
Statins
Benefits: reduce the levels of LDLs, increase levels of HDLs lowering blood cholesterol
Risks: Can take a while to be effective, need to be taken long-term, side effects like muscle pain, liver damage, neurological issues
Anticoagulants
Benefits: Reduce formation of new blood clots, can reduce size of existing blood clots
Risks: May cause excessive or internal bleeding, side effects like fainting, osteoporosis + tissue swelling
Platelet inhibitors
Benefits: reduce formation of blood clots
Risks: Can cause excessive bleeding after injury, side effects like liver damage, rashes and stomach lining damage, cannot be combined with multiple
