Pathology of Hypertension

Question 1

describe classification of hypertension

Answer 1

according to cause;
primary
secondary

consequence (clinicopathological);
benign
malignant

Question 2

describe primary hypertension

Answer 2

90% of cases
no obvious cause
genetic factors 
salt intake - 25% salt sensitive 
protein intake 
renin - angiotensin system
sympathetic activity

Question 3

describe salt sensitive hypertension

Answer 3

increase in dietary salt leads to increase in BP
genetic polymorphisms
some cases of primary hypertension
controlled by reduced salt diet
in renal disease 2y hypertension is usually salt sensitive

Question 4

describe secondary hypertension

Answer 4

underlying disease is implicated;
renal disease
endocrine disease
aortic disease
renal artery stenosis
drug therapy

Question 5

describe renal causes of hypertension

Answer 5

any renal disease - including renal artery stenosis, acute or chronic glomerulonephritis, chronic pyelonephritis, cystic diseases, interstitial nephritis

due to;
reduced renal blood flow
excess renin release
salt and water overload

Question 6

describe endocrine causes of hypertension

Answer 6

adrenal gland hyperfunction/tumours
Conn’s syndrome - excess aldosterone
Cushing’s syndrome - excess corticosteroid
pheochromocytoma - excess noradrenaline

Question 7

describe other causes of hypertension

Answer 7

coarctation of aorta - congenital narrowing of segments of aorta
drugs - including corticosteroids

Question 8

describe bengin hypertension

Answer 8

cause of serious life threatening morbidity
asymptomatic, incidental finding often health checks
eventually causes;
left ventricular hypertrophy (can cause sudden death) - increased left-ventricular load, poor perfusion, interstitial fibrosis, micro-infarcts and diastolic dysfunction
congestive cardiac failure
increases atheroma
increases aneurysm rupture - aortic dissection, Berry aneurysms
renal disease

every 10 mmHg of diastolic pressure above 85 doubles risk of MI
every 8 mmHg of diastolic pressure above 85 doubles risk of stroke

Question 9

describe microvascular inury

Answer 9

blood vessel wall changes - small arteries and arterioles
retina and kidney
thickening of media (smooth muscle)
hyaline arteriosclerosis - plasma proteins forced into vessel wall (cf ageing)

Question 10

describe malignant hypertension

Answer 10

serious threatening condition
diastolic pressure > 130-140
can develop from either benign primary or secondary hypertension (accelerated hypertension), or arise de-novo
needs urgent treatment to prevent death

Question 11

describe pathophysiology of malignant hypertension

Answer 11

cerebral oedema - seen as papilloedema (swelling of optic disc)
acute renal failure
acute heart failure
headache and cerebral haemorrhage
blood vessels show fibrinoid necrosis and endarteritis proliferans of their walls

Question 12

describe pregnancy associated hypertension

Answer 12

common - 10% of pregnancies
increased maternal and fetal morbidity and mortality
pre-eclampsia - hypertension and proteinuria;;
resolves following birth
eclampsia - obstetric emergency

hypertension secondary to silent renal or systemic disease