CV Flashcards
Give and explain the risk factors for atherosclerosis?
Risk factors for atherosclerosis
- Age - increased time to develop
- Smoking - damage to endothelium
- Diabetes - changes in plaque composition
- Obesity - increased inflammatory cytokines
- Family history
- Increased BP - turbulance
- Increased choloesterol - LDL
What does an atherosclerotic plaque contain?
Lipids, necrotic core, connective tissue with a fibrous cap
When does atherosclerosis occur?
Atherosclerosis occurs when there is an injury to the endothelium which leads to endothelium dysfunction.
Injury - cytokines are released - leukocytes are attracted and invade and accumulate in the vessel
Give the 4 main stages of the progression of atherosclerosis
- Fatty streaks - occur in children
- Intermediate lesion - ‘foam cells, SM cells, T cells, platelets
- Fibrous plaque/advanced lesion - covered by a dense fibrous plaque or collagen and elastin overlying the lipid core with necrotic debris
- Plaque rupture - plaque constantly being resorbed & redeposited. May rupture if balance sways towards inflammatory conditions which makes the cap weaker.
Explain how statins work to reduce your cholesterol
Statins inhibit HMG-CoA reductase, the enzyme that controls enzyme production in the liver.
Reduced cholesterol synthesis - reduced intracellular cholesterol in hepatocytes -
= Hepatocytes increased the production of LDL receptors
= Increased LDL receptor mediated uptake in the liver (& VLDL)
= Reduced serum conc of LDL
What are plaques of clinical relevance?
Problems:
Rupture - thrombosis can grow leading too…
Occlusion = Ishaemia
Give the 4 clinical manifestations of atherosclerosis
- Embolism
- Stenosis (narrowing)
- Occlusion
- Aneuyrism (due to weakend walls)
What is angina caused by?
Angina is chest pain due to a mismatch of O2 demand and supply
Give the exacerbating factors that lead to a reduced supply for angina
Reduced supply (blood/O2)
Anaemia
Hypoxemia
Polythemia
Hypothermia
Hypovolaemia
Hypervolaemia
Give the exacerbating factors that lead to an increased demand that cause angina
Increased demand
Hypertension (high BP)
Tachyarrhythmia (high HR)
Valvular HD
Hyperthyroidism
Hypertrophic cardiomyopathy
At which precentage occlusion does ischaemia occur?
a) 5%
b) 25%
c) 55%
d) 75%
Ischaemia occurs at about 75% occlusion
Explain how as diseased artery can cause SOB on exertion?
Stenosed artery cannot relax to reduce resistance
P=QR
High amounts of P needed to increase Q(flow)
Q cannot increase to meet the higher demands
Not enough O2 = drive to breath = SOB
What is crescendo angina?
Crescendo angina occurs at rest or after minimal exertion
Describe the type of pain that is typical of angina
Angina pain
= Fist to chest / band around chest
= Heavy / severe
What are the cardiac symptoms associated with angina?
Chest pain, breathlessness, fluid retention, palpitation, syncope/pre-syncope
Which of the following is not included in a typical history for angina
a) Radiates to the shoulder/face
b) Doesn’t stop after rest
c) Starts on exertion
d) Occurs in the middle of the chest
b) Doesn’t stop after rest
Typical history:
Onset = exertion,
Position = middle of chest
Quality = tight & heavy
Radiation = arms/shoulders/jaw
Relieving = resting
(OPQRST)
What could be a differential diagnosis for chest pain and what are the differences?
PE - breathlessness, blood in cough, swollen legs
Pericarditis/myocarditis - pain like a knife
Disection of the aorta - tearing pain going around to the back
Gastro-esophageal reflux - burning and after a meal
MS - take history
Chest infection/pleurisy
On exercise testing, what would the ECG show if it was angina?
ST depression
Name the drugs which are suitable to treat angina
Aspirin
B-Blockers
Nitrates - GTN & LA
Statins
ACE inhibitors
Ca2+ channel blockers
K+ channel openers
Drugs that stop the plaque growing (antiplatelet) and stop the heart working as hard)
Explain how beta blockers work to stop angina
B1 blockers:
- ve choronotrophic = reduce HR
- ve inotrophic = reduce LV contraction
= Less work & less O2 demand
B2 blockers: peripheral vasoconstriction & broncospasm
Give 2 examples of beta blockers
Propranol = non-selective
Bisopranol = B1 selective
How do nitrate drugs work to reduce angina?
Nitrates GTN & LA
LA - metabolised in liver to NO3
NO3 = endothelial relaxant
= vasodilation of veins and large arteries
= reduced pre-load & work the heart has to do
What are the 4 features of aspirin which are desirable when using it to treat angina?
Anti-platelet - decrease platelet aggregation
Antipyretic
Anti-inflammatory
Analgesic
What does hypertension increase your risk of?
Hypertension increases your risk of:
Stroke
MI
HF
Chronic renal disease (CRD)
Atrial fibrillation
Define stage 1 and 2 hypertension
Stage 1:
Clinical BP = 140/90mmHg AMBP = 135/80 mmHg
Stage 2:
Clinical BP = 160/100mmHg AMBP = 150/95mmHg
When do you treat stage 1 and stage 2 hypertension with antihypertensives?
Hypertension
Stage 1: <80 with one of the following -
Organ damage, renal disease, cardiac problems, diabetes & 10 year CV risk of 20%/<
Stage 2: treat at any age
List the drug types which can be used to treat hypertension
Drugs that can be used to treat hypertension:
ACE-I
Beta-blockers
CCB
A1- blockers
ARD
Aldosterone antagonists
Renin inhibitors
Centrally acting
Which of the following is an ACE-I that could be used to treat hypertension
a) Enalapril
b) Valsartan
c) Verapamil
d) Furosemide
These are all drugs which can be used to treat hypertension but there is only one ACE-I
Enalapril = ACE-I
Valsartan = ARB
Verapamil = Phenylalkylamine CCB
Furosemide = Diuretic
Explain the ways that angiotensin II can be used to prevent hypertension
Angiotensin II normally causes:
- Aldosterone release - increases Na+ and H20 retention leading to increased blood volume
- Peripheral resistance (increased TPR)
- Vascular growth - hyperplasia and hypertrophy of SM cells
Less angiotensin II = Reduced blood volume + reduced peripheral resistance
What are the main AE from ACE-I
ACE-I AE:
ACE-I main effect significantly reduces the amount of AII
Due to reduced angiotensin II = hypotension, actute renal failure, hyperkalaemia, teratogenic effects in pregnancy.
AII inactivates chemical medicators - if lower there is an increase in kinins
AE due to kinin increase = cough, rash, anaphalactoid reactions