Pathology of hypertension Flashcards
Define hypertension
disorder in which the level of sustained arterial pressure is higher than expected for the age, sex, and race of the individual
What do WHO classify as hypertension?
140/90would be accepted as hypertension
What is the aetiology of hypertension?
Cardiac failure
What is hypertension a risk factor for?
Cerebral haemorrhage
Atheroma
Renal failure
Sudden cardiac death
What is CO determined by?
HR
Contractility
Blood volume
What is primary hypertension caused by?
No obvious cause
- genetic factors
- salt intake
- protein intake
- RAAS
- sympathetic activity
What increased dietary salt cause?
Salt sensitive hypertension
Is there a genetic component to Salt sensitive hypertension?
yes
polymorphisms
What is implicated in secondary hypertension?
Underlying disease
- renal disease
- endocrine disease
- aortic disease
- renal artery stenosis
- drug therapy
What are the renal causes of secondary hypertension?
- renal artery stenosis
- acute or chronic glomerulonephritis
- chronic pyelonephritis
- cystic disease
- interstitial nephritis
reduced renal blood flow, excess renin release, salt and water overload
What are some endocrine causes of secondary hypertension?
Adrenal gland hyperfunction/ tumours
conn’s syndrome- excess aldosterone
cushings syndrome- excess corticosteroid
phaeochromocytoma- excess noradranline
What are some other causes of secondary hypertension?
Coarctation of the aorta- congenital narrowing of segments
drugs- corticosteroids
What is benign hypertension?
Asymptomatic, incidental finding due to other pathology
What does benign hypertension cause?
- LVH
- Congestive Cardiac Failure
- Increases atheroma
- increased aneurysm rupture (aortic dissection, berry aneurysms)
- renal disease
What does left ventricular hypertrophy result in?
Increased LV load Poor perfusion Interstitial fibrosis Micro-infarcts Diastolic dysfunction
What is the aetiology of LVH?
Sudden cardiac death (Arrythmia and poor perfusion)
Cardiac failure
affects outcome of other disease
What is a subarachnoid haemorrage?
Bleeding in the brain
Can be caused by a berry aneurysm rupture
1
In benign hypertension every –mmHg of diastolic pressure above 85 ——- the risk of MI
10
doubles
In benign hypertension every -mmHg of diastolic pressure above 85 ——- risk of stroke
8
doubles
What is microvascular injury?
Blood vessel wall changes- small arteries and arterioles
Where might microvascular injury occur?
Retina and kidney
What are the histological changes of microvascular injury?
Thickening of media (smooth muscle) and hyaline arteriosclerosis- plasma proteins forces into vessel wall (cf ageing)
What is malignant hypertension defined as?
Diastolic pressure > 130-140
What is the aetiology of malignant hypertension?
Cerebral oedema acute renal failure acute heart failure headache and cerebral haemorrhage blood vessels show fibrinoid necrosis end endarteritis proliferans of their walls
