Atherosclerosis + Thrombus + Embolism Flashcards
(28 cards)
What is an atheroma and what is in it and what does it cause
Formation of plaques in arteries
Plaque has lipid core full of debris from MO
Fibrous cap has inflammatory cells
Leads to
Plaque stiffen = hypertension
Stenosis = reduced flow = angina
Can become inflamed and thrombus = IHD / ACS
What is the pathology of formation of atheroma
Endothelial injury - smoking / high HDL / HTN
Chronic inflammation
LDL aggregate
Free radicals turn LDL into lipids = inflammation
MO phagocytose LDL into
toxic foamy macrophages
Fatty streak forms
Enhanced expression for cell adhesion (ICAM1 + E selection)
High permeability for LDL + platelets
Growth factor PDGF released from platelet = proliferation
Inflammation + inflammatory cells recruited
Smooth muscle proliferation
Fatty streaks becomes atherosclerotic plaque which can cause stenosis or thrombosis
What are the RF for atheroma
Non modifiable and modifiable
Non-modifiable
- Age
- FH
- Male
Modifiable Smoking Alcohol Diet Hypercholesterolaemia - high LDL, low HDL Hypertension DM CKD RA as inflammatory process Atypical anti-psychotic
Less strong
Obesity
Inactivity
Low birth weight
How do you investigate atherosclerosis
Bloods - LDL, HDL, cholesterol, triglycerides
Carotid USS - flow (radius decreases, velocity increases)
Ausculate - bruit = stenosis
Neuro exam
What is primary prevention of atherosclerosis
Never had CVS event Smoking cessation Control BP Weight loss Exercise Control DM Statin 20mg + aspirin 75mg
What is secondary prevention (prevent another event)
Statin - 80mg Aspirin (inhibit platelet aggregation) BB titrate to max ACEI titrate to max Surgery
What surgery can be done
Bypass - CABG
Stenting - (no GA + minimally invasive and reduce risk of stroke)
Carotid endarectomy if >70% stenosis - open up and remove plaque in common carotid, internal or external
What are risks of surgery
What nerves affected
Endarectomy Stroke / MI Infection Bleeding Scar Anaesthetic GA Nerve damage Recurrent laryngeal = hoarse Sympathetic = Horner Hypoglossal = tongue deivation
Stenting
- Emboli
- Groin haematoma
- Radiation
- Contrast nephrotoxicity
What are complications of stable atheroma occluding blood flow
Stable angina
Coronary artery stenosis
Peripheral vascular disease
When does a plaque become complicated
Haemorrhage into plaque causing calcification
Plaque rupture leading to thrombus which travels and blocks distal = ischaemia (ACS / stroke / TIA)
What are the complications of plaque rupture
Activation of coagulation as contents exposed
Thrombis + embolism
ACS (Unstable angina +MI)
Stroke
Aneurusm / AAA as calcification weakens walls
What determines flow through vessel
Pressure difference / Resistance
What determines resistance
Vessel length x (viscosity / radius)
Guidelines following TIA / non disabling stoke
BMT to all patient
Carotid imaging within 1 week
If no significant stenosis = BMT
If significant >70% = refer for endarectomy
When do you start primary prevention
If QRISK >10% risk of event in 10 years
or if CKD / type 1 DM for 10 years
What should you check when start statin
Lipids at 3 months - aim for 40% reduction
LFT at 3 months and 12 months
Monitor for rhabdomyolysis
What can statin cause
Myopathy
Type II DM
Risk of rhabdomyolysis if with macrolide AX
Rarely haemorrhagic stroke
What is a thrombus
Solid mass of blood constituents within vascular system
What causes thrombus
Virchow’s
- Change in vessel wall
- Change in blood constituents
- Change in blood flow
What causes change in vessel wall
Atheroma as causes tuburlent flow
Exposes collagen leading to platelet and fibrin adhesion
Enlarges
What causes change in blood flow
Stasis e.g. post-op / travel Atheroma = turbulent flow AAA Hyperviscosity Spasm of vessel External compression Vasculitis
What causes change in blood constituents
High cholesterol / LDL
Hypercoagulable
Surgery
What is a mural thrombus
Thrombus in heart
- MI
- AF
- Atrial dilatation
What does it lead too
PE if on ride side
Stroke / renal infarct / bowel ischaemia if L side
