Hypertension

Question 1

What is hypertension?

Answer 1

140/90mmHg.
Benefits from treatment with hypertensive agents in reducing cardiovascular, cerebrovascular and peripheral vascular risk.

Question 2

What is the prevalence of hypertension?

Answer 2

30-40% of the adult population.
>50% of >60yr olds.
A risk factor for MI and stroke.

Question 3

What are the complications of hypertension?

Answer 3

Heart - LVH, CHD, CHF, MI.
Peripheral vascular disease.
Eyes - retinopathy.
Affects the brain and kidneys.

Question 4

What are the different stages of hypertension?

Answer 4

Stage I - >140/90.
Stage II - >160/100.
Stage III - >180/120.

Question 5

What are the types of hypertension?

Answer 5

Primary - 90% of cases (idiopathic).

Secondary - 10% of cases. Caused by chronic renal disease, renal artery stenosis, or endocrine diseases (Cushing’s, Conn’s)
Incidence is highest in the young.

Question 6

What are the risk factors of hypertension?

Answer 6

Smoking.
Diabetes (10x risk of MI).
Renal disease.
Male (2x risk).
Hyperlipidaemia.
Previous MI or stroke.
LVH (2x risk).
Lifestyle (exercise, diet).

Question 7

How is age related to hypertension?

Answer 7

BP rises with age.
Aggressive BP treatment in the elderly can reduce the risk of stroke and MI.

Question 8

How are genetics related to hypertension?

Answer 8

Familial hypertension (between siblings).
>30 recognised important genes, but individually account for <0.5mmHg each.

Question 9

How is the environment related to hypertension?

Answer 9

Mental and physical stress increase BP.
White coat hypertensive patients have an increased risk of CVD.

Question 10

How is diet related to hypertension?

Answer 10

A strong relationship between hypertension, stroke, and salt intake.
Reducing salt intake in hypertensive individuals does lower BP (difficult to restrict).

Question 11

How is alcohol related to hypertension?

Answer 11

Small amounts tend to decrease BP.
Large amounts tend to increase BP.
Reduced consumption causes a decrease in BP over several days to weeks (small).
A common cause in young men.

Question 12

How is weight related to hypertension?

Answer 12

Obese patients have a higher BP.
Weight loss causes a fall in BP.

Lower birth weight increases risk of hypertension development in later life.

Question 13

How is race related to hypertension?

Answer 13

Black populations genetically retain salt more, and are more sensitive to changes in sodium.

Question 14

What are the likely causes of hypertension?

Answer 14

Increased reactivity of resistance vessels - a hereditary defect of arteriolar smooth muscle.

Kidneys are unable to excrete enough Na+ for any given BP, so Na+ is retained, and BP increases.

Question 15

What is the basis of treatment for hypertension?

Answer 15

Targeting SNS and RAAS.
Confirm diagnosis, assess risk factors, then assess end organ damage.

Question 16

What are the investigations for end organ damage?

Answer 16

LVH - ECG / ECHO.
Proteinuria - urinalysis.
US - renal function.

Question 17

What conditions are screened for in hypertension?

Answer 17

Renal artery stenosis.
Conn’s / Cushing’s.
Coarctation.
Drug induced.
Sleep apnoea.

Question 18

What is Q-Risk?

Answer 18

Once risk has been assessed, set a target BP (<135/85). Start treatment when CVD risk is <10% in 10yrs.

Question 19

How does treatment change with the staging of hypertension?

Answer 19

Stage I - antihypertensives for <80yr old patients with >135/85 and organ damage, established CVD, renal disease or diabetes.
Stage II - antihypertensives (>150/95).

Question 20

How does the treatment of hypertension change with age?

Answer 20

For <40yr olds with any staging of hypertension, seek specialist evaluation of secondary causes of hypertension, and a more detailed assessment of potential organ damage.
For >80yr olds, also consider any co-morbidities.

Question 21

What is the first step in choosing antihypertensives?

Answer 21

For >55yrs old, and black people of African or Caribbean family origin of any age) - CCB or a thiazide diruetic.
For <55yrs old - ACEI/ARB.

Not Afro-Caribbean - less effective, risk of angioedema.
Not child-bearing women - teratogenic in early stages, toxic to foetuses in later stages.

Question 22

What are the consequent steps in choosing hypertensives?

Answer 22

Step 2 - add thiazide diuretic.
Step 3 - CCB, ACEI, and diuretic.

Step 4 (resistant hypertension) - consider compliance issues and higher dose thiazide diuretic treatment if blood K+ > 4.5mmol/L.
Consider further diuretic therapy with low-dose spironolactone.

Question 23

What are antihypertensive drugs?

Answer 23

ACEIs (Ramipril, Perindropril).
Competitively inhibits ACEs.
Contraindications - hyperkalaemia, renal artery stenosis, fertile female.
With NSAIDs - renal failure.

Question 24

What are ARBs?

Answer 24

Losartan, valsartan, candesartan.
Fewer side effects compared to ACEIs.
No cough.

Question 25

What are CCBs?

Answer 25

Amlodipine and felodipine - vasodilators.
Nifedipine - women of childbearing age.
Used in >55yr olds.

Verapimil - rate limiting.
Reduces HR, and some vasodilation.
Bradycardia and constipation.

Question 26

What are the contraindications and ADRs of CCBs?

Answer 26

Contraindications - acute MI, heart failure.
ADRs - flushing, headache, ankle oedema.

Question 27

What is indapamide?

Answer 27

A thiazide diuretic.
First line treatment in mild/moderate hypertension in Afro-Caribbeans.
Can be used with other hypertensives.
Stroke and MI reduction.

Question 28

What are the negative effects of thiazide diuretics?

Answer 28

Enhances the urinary excretion of sodium and reduces peripheral vascular resistance.
ADRs - gout, ED (not common).

Question 29

What are uncommon agents used for the treatment of hypertension?

Answer 29

Doxazosin - opposes arterial smooth muscle concentration (ADRs - dry mouth, dizziness).

Methyldopa - used in pregnancy (ADRs - nasal congestion, orthostatic hypotension).

Hydralazine and minoxidil - vasodilators.

Question 30

What are common treatment regimes for hypertension?

Answer 30

Age >55 or Afro-Caribbean:
CCB - thiazide - ACEI/ARB - beta blocker - uncommon agents.

Age <55:
ACEI - thiazide - CCB - beta blocker - uncommon agents.