7. Heart and blood vessels- atheroma Flashcards
Diseases
Numerous diseases of the heart and blood vessels
Concentrate today on the most common- atheroma and ischaemic heart disease
Some other conditions will be covered in the second lecture
Atheroma:
“build-up of fatty material on the inside wall of an artery”
Atherosclerosis:
“the progressive narrowing and hardening within an artery potentially resulting in a complete blockage”
Epidemiology- atheroma
Contributes to almost half of all deaths in Western countries
Affects arteries- slowly progressive
Lower abdominal aorta, coronary arteries, popliteal arteries, internal carotid arteries and vessels of circle of Willis
Pathogenesis
Initiated by chronic injury to the endothelium (response to injury hypothesis) resulting in chronic inflammation
Causes of injury
Hyperlipidaemia, disturbed flow, smoking, hypertension
Progresses as white cells, fat and blood constituents infiltrate injury
Pathogenesis- Stages of atheroma
Type I: Initial lesion Isolated macrophage foam cells
Type II: Fatty streak lesion Mainly intracellular accumulation
Type III: Intermediate lesion Type II changes with small extracellular lipid pools
Type IV: Atheroma lesion Type II changes and core of EC lipid
Type V: Fibroatheroma lesion Lipid core and fibrotic layers, or mainly calcific, or mainly fibrotic
Type VI: Complicated lesion Surface defect, hematoma-hemorrhage, thrombus
Clinical manifestation
Can occur in any artery:
Coronary artery- heart attacks/angina(ischaemic heart disease
Aorta- aneurysm due to weakening of the wall
Carotid- narrowing causing strokes
Peripheral vascular disease
Complications
Atherosclerotic plaques develop slowly over decades but may acutely cause symptoms due to: Aneurysm and Rupture Thrombosis Haematoma formation Embolisation Development of critical stenosis
Clinical Manifestation Case 1- Stroke
A 65 year old gentleman with a history of hypertension presents with sudden onset dysphasia, left arm and leg weakness.
He had a similar episode 2 weeks ago, but it only lasted 1 minute.
Cerebral infarction (Stroke)
Clinical Manifestation Case 2
A 70 year old gentleman who has smoked for most of his life has attended clinic.
Over the last year he has had severe pain in both his legs when walking for more than 10m, and has had a number of infected ulcers in his feet and lower legs requiring antibiotics.
Peripheral Vascular Disease
Clinical Manifestation Case 3
50 year old gentleman with type 2 diabetes presents with 30 minute history of ‘central, crushing chest pain’.
The ECG showed marked ST elevation affecting V1 to V4.
The gentleman was taken to the cath lab for a revascularisation procedure (primary percutaneous coronary intervention(PCI)).
MYOCARDIAL INFARCT (Heart Attack)
Other presentations
Bowel ischaemia
Renal artery stenosis
Emboli
Treatment
Revascularization
Secondary prevention
Epidemiology- Ischaemic Heart Disease
Largest single cause of death in the UK
Mortality has fallen considerably over the last few years, interventions more sophisticated
≈ 60 deaths per 100,000 each year
One MI increases risk of developing heart failure and stroke 3-6 fold
Aetiology
Imbalance between supply (perfusion) and demand of the heart for oxygenated blood
Important:
Not only ↓ oxygen but also ↓ nutrient substrates and inadequate removal of metabolites
