hypertension

Question 1

definition of HTN

Answer 1

Defined as systolic BP >140mmHg and/or diastolic BP>85mmHg measured on three separate occasions.

Question 2

definition of malignant HTN

Answer 2

BP >=200/130mmHg.

Question 3

aetiology of HTN

Answer 3

primary - essential/idiopathic HTN - commonest >90% cases

secondary

• renal - renal artery stenosis, chronic glomerulonephritis, chronic pyelonephritis, polycystic kidney disease, chronic renal failure, polyarteritis nodosa, systemic sclerosis, atheroma, fibromuscular dysplasia
• endo - dm, hyperthyroidism, cushings syndrome, conn’s, hyperparathyroidism, phaeochromocytoma, congenital adrenal hyperplasia, acromegaly
• CVS - aortic coarctation, raised intravascular volume
• drugs - Sympathomimetics, corticosteroids, oral contraceptive pill, MAOI, cocaine, amphetamines
• preg - pre-eclampsia
• liquorice

Question 4

pathology of HTN

Answer 4

fibrotic intimal thickening of arteries, reduplication of elastic lamina and smooth muscle hypertrophy

arteriolar wall layers replaced by pink hyaline material with luminal narrowing

Question 5

white coat and masked HTN

Answer 5

white coat hypertension - elevated clinic pressure, normal ABPM. dont treat, but increased risk of developing HTN in future and CVD

masked hypertension is the opposite

Question 6

malignant or accelarated phase HTN

Answer 6

A rapid rise in BP leading to vascular damage (pathological hallmark is fibrinoid necrosis).

• severe hypertension (eg systolic >200, diastolic>130mmHg) + bilateral retinal haemorrhages and exudates; papilloedema may or may not be present.
• Symptoms are common, eg headache ± visual disturbance.
• It requires urgent treatment, and may also precipitate acute kidney injury, heart failure, or encephalopathy, which are hypertensive emergencies.
• Untreated, 90% die in 1yr; treated, 70% survive 5yrs.
• It is more common in younger and in black subjects.
• Look hard for any underlying cause.

Question 7

epidemiology of HTN

Answer 7

Very common.

10–20% of adults in the Western world.

Question 8

sx of HTN

Answer 8

asymptomatic

symptoms of complications

symptoms of cause

Question 9

sx of accelarated HTN

Answer 9

scotomas - visual field loss

blurred vision

headache

seizures

nausea

vom

acute HF

Question 10

signs of HTN

Answer 10

Measure on two to three different occasions before diagnosing hyper-tension and record lowest reading.

loud 2nd heart sound

4th heart sound

examine for causes:

• radiofemoral delay, weak femoral pulse (aortic coarction)
• renal artery bruit (renal artery stenosis)
• palpable kidney
• cushings

end organ damage - fundoscopy for retinopathy, LVH, proteinuria - indicates severity = worse prognosis

Question 11

Keith–Wagner classification of retinopathy

Answer 11

(I) ‘silver wiring’;

(II) as above, plus arteriovenous nipping;

(III) as above, plus flame haemorrhages and cotton wool exudates;

(IV) as above, plus papilloedema.

Question 12

Ix for HTN

Answer 12

• blood - UE, glucose, lipids, ca
• urine dipstick - blood and protein
• ECG
• echo - LVH, past MI
• Ambulatory BP monitoring (BP measured throughout the day)
• fasting glucose
• cholesterol
• Renal ultrasound/arteriography (renal artery stenosis);
• 24h urinary meta-adrenaline
• urinary free cortisol
• renin
• aldosterone
• MR aorta - coarctation
  *

Question 13

ECG for HTN

Answer 13

LVH: deep S wave in V1–2, tall R wave in V5–6,inverted T waves in I, aVL, V5–6, left-axis deviation)

ischaemia.

Question 14

why do ambulatory BP monitoring

Answer 14

Excludes ‘white coat’ hypertension,

monitoring of treatment response,

assesses preservation of nocturnal dip.

Question 15

Mx approach for HTN

Answer 15

assessment and modification of CVS risk factors

treat underlying causes

conservative

• stop smoking
• lose weight
• reduce alcohol
• reduce dietry Na
• increase exercise

investigate for secondary causes - young patients, malignant hypertension or poor response to treatment

Reduce blood pressure slowly; rapid reduction can be fatal, especially in the context of an acute stroke.

medical

Question 16

target BP

Answer 16

140/80 non-dm

130/80 dm without proteinuria

125/75 dm with proteinuria

150/90 if >80yrs

Question 17

Mx of acute malignant HTN

Answer 17

IV b-blocker, labetolol or hydralazine sodium nitroprus-side.

Avoid very rapid lowering which can cause cerebral infarction. bed rest.

Oral therapy unless encephalopathy or CCF

Question 18

approach to encaphalopathy in HTN

Answer 18

headache, focal CNS signs, seizures, coma

aim to reduce BP to 110 diastolic over 4hrs

admit

arterial line

Either IV labetalol (eg 50mg IV over 1min, repeated every 5min, max 200mg) or sodium nitroprusside infusion (0.5mcg/kg/min IVI titrated up to 8mcg/kg/min, eg 50mg in 1L glucose 5%; expect to give 100–200mL/h for a few hours only, to avoid cyanide risk).

Question 19

medical Mx of HTN

Answer 19

Question 20

complications of HTN

Answer 20

HF

CAD and MI

CVA

PVD

emboli

retinopathy

renal failure

hypertensive encephalopathy

posterior reversible encephalopathy syndrome

malignany hypertension

premature death

50% of all vascular deaths

Question 21

Px of HTN

Answer 21

good if BP controlled

Uncontrolled hypertension linked with increased mortality (6x stroke risk and 3x cardiac death risk).

Treatment reduces incidence of renal damage, stroke and heart failure.

Question 22

when to treat HTN

Answer 22

Question 23

persistent HTN

Answer 23

High blood pressure at repeated clinical encounters

Question 24

stage 1 HTN

Answer 24

clinic: 140/90 - 159/99

ABPM or HBPM 135/85 - 149/94

Question 25

stage 2 HTN

Answer 25

clinic - 160/100 - 180/120

ABPM or HBPM >150/95

Question 26

stage 3 HTN

Answer 26

clinic - >180/120