L16 - drug treatments of cardiovascular disease

Question 1

define atherosclerosis

Answer 1

build up of cholesterol rich plaques in major arteries causing narrowing of these arteries

Question 2

what are the components of an atherosclerotic plaque

Answer 2

1. fibrous cap (SM and connective tissue)

2. lipid core

Question 3

what is atherogenesis

Answer 3

development of plaques

Question 4

describe process of atherogenesis

Answer 4

1. macrophages penetrate artery walls and stay there taking up lipids - creating fatty streak
2. legion grows and grows creating plaque and narrowing artery

Question 5

how is fatty streak formed in arteries

Answer 5

macrophage penetrates into artery wall and stays there taking up lipids

Question 6

what is thrombosis

Answer 6

blood clot

Question 7

what can happen if an atherosclerotic plaque ruptures?

Answer 7

can cause thrombosis leading to MI/stroke

Question 8

when will symptoms of an atherosclerotic plaque be noticed?

Answer 8

when it narrows the artery - causing angina for example

Question 9

what type of plaques are prone to ruptures?

Answer 9

those with thin fibrous cap

Question 10

what is a stable plaque

Answer 10

thick fibrous cap
greatly narrows artery
loss of coronary flow reserve

Question 11

what is a vulnerable plaque

Answer 11

a plaque that has:
thin fibrous cap
large lipid core
prone to rupturing

can rupture and cause thrombosis

Question 12

what is angina

Answer 12

temporary chest pain usually during exercise due to less blood flow to coronary arteries

Question 13

what ways can drugs treat angina?

Answer 13

1. decrease cardiac workload and o2 demand

2 increase o2 supply to ischemic zone by dilating arteries

Question 14

what drugs can treat angina (6)

Answer 14

1. organic nitrates - vasodilation
2. B blockers - decrease HR & contractility (and o2 demand)
3. ivabradine - decreases HR and therefore decreases work and o2 demand
4. ranolazine - decreases cardiac stiffness (so decreases workload and o2 demand)
5. Ca2+ channel blockers - vasodilators and decrease afterload
6. nicorandil - vasodilator

Question 15

what does ivabradine do

Answer 15

decreases HR and therefore decreases work and o2 demand of heart
treat angina

Question 16

what does ranolazine do

Answer 16

decreases cardiac stiffness (incorrect contraction) so decreases workload and o2 demand
can treat angina

Question 17

how do Ca2+ channel lockers treat angina

Answer 17

they decrease afterload and cause vasodilation

so decrease work and o2 demand

Question 18

how do B blockers treat angina

Answer 18

they decrease HR and contractility

therefore decreasing workload and o2 demand

Question 19

how does nicorandil treat angina

Answer 19

vasodilator of arteries and veins
decreases preload and afterload
therefore decreases workload and o2 demand

Question 20

what receptors mediate contractility of heart?

Answer 20

stimulating B1 receptors

Question 21

in what two ways does decreasing HR help angina?

Answer 21

it decreases workload and o2 demand

also increases blood flow to coronary arteries of LV

Question 22

how does decreasing HR increase coronary flow to the LV

Answer 22

during contraction the LV compresses bvs in its wall so the LV only gets blood flow during diastole(relaxation)

slowing HR increases the amount of time spent in diastole

Question 23

how does atherosclerotic plaque cause myocardial infarction

Answer 23

1. plaque rupture in coronary artery
2. platelet aggregation and coagulation cause thrombosis
3. regional ischemia causes progressive cardiac cell death

Question 24

what are the consequences and treatments of cardiac ischaemia

Answer 24

1. ventricular fibrillation - defibrillator
2. severe pain and nausea - morphine
3. poor contractility then cell death - remove thrombus

Question 25

what is chronic heart failure

Answer 25

when CO is not sufficient due to poor contractility

Question 26

symptoms of chronic heart failure

Answer 26

1. oedema
2. breathlessness
3. enlarged but weaker heart

Question 27

describe process of cardiac remodelling

Answer 27

1. stimulus causes fall in CO which activates RAA system and SNS
2. these compensate and restore CO
3. the stimulus remains so these systems stay activated for prolonged period of time causing cardiac remodelling

Question 28

what are the aims of drugs used to treat chronic HF

Answer 28

1. reduce cardiac remodelling

2. treat symptoms

Question 29

what drugs can reduce cardiac remodelling?

Answer 29

1. ACE inhibitors (inhibit production of angiotensin2)
2. B1 blockers (decreases SNS stimulation)
3. aldosterone antagonists

Question 30

why are aldosterone antagonists used as treatment for CHF

Answer 30

aldosterone leads to increased connective tissue in heart which lowers contractility
inhibiting this will help contractility

Question 31

what can treat acute HF

Answer 31

B1 agonist

Question 32

what lifestyle changes can decrease hypertension

Answer 32

lose weight
eat less Na+
exercise
less stress

Question 33

what are the two things thought to be the main cause on hypertension

Answer 33

1. RAA system as it causes water retention

2. SNS overactivity as it causes vasoconstriction

Question 34

what drugs are used to treat hypertension

Answer 34

vasodilators
diuretics
ACE inhibitors (RAA system)

Question 35

what are statins and what do they do

Answer 35

statins that reduce cholesterol levels by decreasing synthesis of cholesterol in liver