Hypertension Flashcards
what is hypertension?
a disorder in which the level of sustained arterial pressure is higher than expected for the age, sex and race of the individual
what is the exact blood pressure considered to be hypertension?
> 140/90
what are the two types of hypertension?
white coat
stable or labile
what does hypertension eventually cause?
cardiac failure
what is hypertension a risk factor for?
cerebral haemorrhage
atheroma
renal failure
sudden cardiac death
describe the incidence of hypertension
varies between countries higher in black populations lower in south pacific familial tendency rises with age
what is the classification of hypertension according to cause?
primary or secondary
what is the classification of hypertension according to consequences?
benign or malignant
how can BP be calculated?
CO X PR
what has an effect on CO?
HR
contractility
blood volume
what has an effect on PR?
constrictors and dilators
describe resistance arteries
peripheral resistance
target organ damage
what is primary hypertension?
most common
no obvious cause
what can be involved in causing primary hypertension?
genetic factors
salt intake
protein intake
which body systems does primary hypertension involve?
RAAS
sympathetic activity
what is salt sensitive hypertension?
increase in dietary salt leads to increase in BP
some causes primary hypertension
controlled by reduced salt diet
what causes salt sensitive hypertension?
genetic polymorphisms
what is secondary hypertension?
when underlying disease is implicated eg renal disease, endocrine disease, aortic disease, renal artery stenosis, drug therapy
what are renal causes of hypertension?
any renal disease
reduced renal blood flow
excess renin release
salt and water overload
name some renal diseases which may cause hypertension
renal artery stenosis, acute or chronic glomerulonephritis, chronic pyelonephritis, cystic diseases, interstitial nephritis
what are endocrine causes?
adrenal gland hyperfunction/tumours
eg conn’s syndrome- excess aldosterone, cushing’s syndrom- excess corticosteroid, phaeochromocytoma- excess noradrenaline
what are other causes?
coarctation of the aorta- congenital narrowing of segments of the aorta
drugs- including corticosteroids
what is benign hypertension?
a cause of serious life threatening morbidity
asymptomatic, incidental finding often health checks
what does benign hypertension eventually cause?
left ventricular hypertrophy congestive cardiac failure increases atheroma increases aneurysm rupture- aortic dissection, Berry aneurysms renal disease
what happens during left ventricular hypertrophy?
increased LV load poor perfusion interstitial fibrosis micro-infarcts diastolic dysfunction
what can LV hypertrophy cause?
sudden cardiac death- arrhythmia and poor perfusion
cardiac failure
affects outcome of other disease
what is a subrachnoid haemorrhage?
rupture of berry aneurysm
what are the figures of benign hypertension?
Every 10mmHg of diastolic pressure above 85 doubles risk of MI
Every 8mmHg of diastolic pressure above 85 doubles risk of stroke
what is microvascular injury?
blood vessel wall changes- small arteries and arterioles
thickening of media (smooth muscle)
hyaline arteriosclerosis
where can microvascular injury occur?
retina and kidneys
what is hyaline arteriosclerosis?
plasma proteins forced into vessel wall
what is malignant hypertension?
serious life threatening condition
diastolic presssure > 130-140
needs urgent treatment to prevent death
how does malignant hypertension arise?
from either primary or secondary hypertension or arise de-novo
what does malignant hypertension cause?
cerebral oedema- papilloedema acute renal failure acute heart failure headache and cerebral haemorrhage blood vessels show fibrinoid necrosis and endarteritis proliferans of their walls
what is pregnancy associated hypertension?
pre-eclampsia- hypertension and proteinuria
hypertension secondary to silent renal or systemic disease
what is stage 1 hypertension?
clinic BP is 140/90 mmHg or higher and ABPM or HBPM daytime average is 135/85 mmHg or higher
what is stage 2 hypertension?
clinic BP 160/100 mmHg or higher and ABPM or HBPM daytime average is 150/95 mmHg or higher
what is severe hypertension?
clinic BP is 180 mmHg or higher or clinic diastolic BP is 110 mmHg or higher
what is the main driver for absolute risk of hypertension?
age
what is the end organ damage of hypertension?
LV hypertrophy
creatinine raised
albuminuria/ microalbuminurira
retinopathy
what drugs are used to treat hypertension?
ACE inhibitors
Beta blockers
Calcium channel blockers
Diuretics (usually thiazide)
what is the benefit of combination therapy?
fewer side effects
what are the characteristics of resistant hypertension?
non-concordance 'white coat' effect pseudo-hypertension lifestyle factors drug interactions secondary hypertension true resistance
which drug is the most effective in treating resistant hypertension?
spironolactone
describe the use of spironolactone
start low; go slow
caution: diabetes and low GFR
describe the treatment of hypertension in under 55s
ACE/ARB or B-blocker if fertile female, calcium antagonist, diuretic, spironolactone
describe the treatment of hypertension in over 55s
calcium antagonist, ACE/ARB, diuretic, spironolactone
what new technologies can be used to treat hypertension?
renal denervation
baro-receptor stimulation
rox coupler
