hypertension

Question 1

what is hyoertension

Answer 1

when you have bp higher than the ideal
the level of bp where investigation can do more harm than good
affects 50% of people

Question 2

describe the bp distribution

Answer 2

unimodal
any distinction between normal and abnormal is arbitrary
hat we accept as normal is lower than what we used to

Question 3

how have the guidelines for bp been updated

Answer 3

ambulatory and home bp (recorded by a machine at any interval that you like) compared to ‘office’ bp
ambulatory is 5-1mmHg lower than Bp in surgeries

Question 4

what is the current practice

Answer 4

lower bp to less than 120mmHg

not always tolerated

Question 5

problem with treating hypertension

Answer 5

30-40% people have hypertension
need to know which ones to treat
when people’s bp is lowered - feel v ill - you need to treat the patient not the condition

Question 6

relationship of bp with age

Answer 6

in advanced countries, the systolic bp rises with age
diastolic stays flat, in v old age it decreases
therefore gap between systolic and diastolic increases with age - this is the pulse pressure
>60 majority people hypertensive
>80 almost everyone is

Question 7

exception when ou’re very old

Answer 7

hypertension is good
if heart strong enough to maintain a high bp it is good enough to work normally
younger though, reducing hypertension reduces strokes - it is important to treat

Question 8

what does the word ‘normal’ mean when describing hypertension in elderly

Answer 8

common

NOT right

Question 9

what is the threshold for bp risk

Answer 9

no reliable threshold

at risk if >110

Question 10

issue woth the fact that bp is continuous

Answer 10

if reduce - risk doesn’t disappear - people with low bp still have attributable DALYs

Question 11

what is secondary hypertension

Answer 11

when there are identifiable causes

Question 12

how much of the hypertension is secondary - %

Answer 12

5% older

15% loung

Question 13

causes of secondary hypertension

Answer 13

renal disease (inc renal artery stenosis)
Conn’s syndrome - tumour secreting aldosterone
phaeochromocytoma - tumour secreting catecholamines - rare
the pill
pre-eclampsia/pregnancu associated hypertension
genetic casues - liddie’s syndrome

Question 14

aetiology of primery hypertension

Answer 14

single genes - involved in Na handling in the kidney 
monogenic rare 
polygenic common 
dietary salt
obestity 
alchohol
birthweight 
pregnancy

Question 15

relationship between bp and genes

Answer 15

30-40% bp variation due to genes
try to find cause in the majority of the population
SNPs only 4% of this
monogenic disease accounts for <1% population - Liddie’s and apparent mineralocorticoid excess
complex polygenic casues - multiple genes with small effects, interaction with sex, other genes and the env
lot of genes but they have a small effect on bp

Question 16

what is associated with hypertension, haemodynamically

Answer 16

increased TPR 
decreased arterial compliance
normal CO 
normal blood vol 
central shift in volume 
small effect in venous circulation

Question 17

what causes elevated TPR in hypertension

Answer 17

vasoconstriction of arteries and arterioles
growth and remodelling - lumen smaller, wall thicker - don’t know if this is an adaption to hypertension or the cause
rarefraction - capillary loss = reduced area for blood flow = increased TPR

Question 18

Describe isolated systolic hypertension

Answer 18

Systolic >140mmHg
Diastolic <90
Increasing stiffness of medium and large arteries
Piles wave reflected - greater by the time it reaches the brachial artery than when it left the heart
TPR doesn’t increase

Question 19

How does the kidney cause primary hypertension

Answer 19

It is involved in no regulation - exciretion of na, regulation of water and ECF
Best evidence in relation to salt intake
Impaired renal function and blood flow is the commonest 2nd cause of hypertension - parenchyma disease Andy stenosis
Almost all monogenic causes affect na excretion
Population size with no salt have low population bp Andy no rise with age
Animals with reduced na handling have high bp
In rats - hypertension translated with a kidney transplantation

Question 20

How do endocrine and paracrine factors cause primary hypertension

Answer 20

Inconsistant evidence

Question 21

How does the SNS cause primary hypertension

Answer 21

High sympathetic activity drives high bp

Activity deminishes woth age but no is still high

Question 22

what does hypertension increase your risk of

Answer 22

CHD
stroke
peripheral vascular disease/atheramotous disease
heart failure
atrial fibrillation
dementia/cognitive impairment - slow deterioration
retinopathy

Question 23

how does hypertension affect the heart

Answer 23

large heart - thick walls
more likely to fail and cause sudden death
arrhythmia and abnormality of heart rhythm

Question 24

how is hypertension related to congestive heart failure

Answer 24

1st and 2nd cause of heart failure
prevalence increasing in contrast to other things
hypertension increases risk 2-3 fold, accounts for 25% of cases
hypertension precedes CHF in 90% of cases, most CHF in elderly is due to hypertension
people live with a bad heart and then get congestive heart failure

Question 25

how is hypertension associated with large arteries

Answer 25

hypertension causes large arteries
intima media thickness 2-3x larger than normal
may cause aneurysms - lead to thrombosis or haemorrhage (weakness in wall, rupture - can happen in the brain)
85% of hypertension related strokes is due to clotting and thrombosis not bursting

Question 26

how is hypertension linked with the eye

Answer 26

retina
swelling of the optic disk- papilledema
extrudates - leakage of blood or plasma into retina = white patches
damage illustrates microvasculature damage
thickening of wall
arteriolar narrowing
vasospasm,
impaired perfusion
increased leakage to surrounding tissue
this mainly happens when people have been on treatment and stop it

Question 27

how is hypertension linked with the microcirculation

Answer 27

reduction in capillary density = impaired perfusion in organ that is affected, increased PVR
elevated capillary pressure = damage and leakage

Question 28

how does hypertension affect the kidney

Answer 28

granular capsular surface 
cortical thinning = renal atrophy 
renal disfunction - albuminuria 
extreme hypertension is rare but leads to rapid progression of renal failure 
subcapsular haemorrhages

Question 29

how is microalbuminuria caused

Answer 29

hypertension causes increased albumin in the urine
reduced GFR
GFR decreases with age anyway

Question 30

action of angiotensin receptor blockers

Answer 30

block receptor stops bad effect in kidney

Question 31

action of ACE inhibitors

Answer 31

reduce ANG 2 production

but it is not completely blocked - made through different pathways

Question 32

do you use ARBs or ACE inhibitors

Answer 32

people generally respond to 1 and not the other

Question 33

action of diuretics

Answer 33

chlorothiazide
only used if in crisis
used when there is a large fluid overload
thiazide diuretics don’t reduce BP by diuresis, lower the PVR but we don’t know how

Question 34

action of B blockers

Answer 34

block B1 receptors in the heart - reduce rate of contraction, reduced CO
block B1 receptors in kidney - reduced secretion of renin, reduced activity of RAAS
not favoured, other drugs better at stopping strokes

Question 35

action of Ca channel blockers

Answer 35

major effect in vascular smooth muscle (block V gated channels) - reduce Ca influx = less myosin actin cross bridging
minor effect in heart - inhibition of Ca influx = reduces contractility, and rate of contraction - negative dermotropy (reduce flow of blood through heart, can be used in atrial fibrillation to slow the heart down)

Question 36

low salt environment and hypertension

Answer 36

lwo salt of env- bp doesn’t rise with age

not common because most people eat a lot of salt