Hypertension

Question 1

What are the prime contributors to blood pressure?

Answer 1

CO = SV x HR

PVR (high PVR = high BP)

Question 2

Aetiology of HPT

Answer 2

Polygenic: major genes and polygenes (obesity, race, BP)

Polyfactorial: environment, individual and shared (stress, oral contraceptive, physical inactivity)

Question 3

What is Primary HPT

Answer 3

Idiopathic

• Genetics
• Obesity
• Alcohol
• Na intake
• Stress

Question 4

What is Secondary HPT

Answer 4

Occurs due to disease

• Renal
• Endocrine - Cushing’s syndrome, Conn’s syndrome
• Congenital - coarctation of aorta
• Pregnancy - pre-eclamsia
• Drugs - oral contraceptive, steroids, NSAIDs
• Sleep Apnoea

Question 5

Symptoms

Answer 5

Usually asymptomatic but sustained HPT produces end organ damage to vessels, heart and kidney

Question 6

Ideal BP

Answer 6

Between 120/80 - 140/90

Question 7

Investigation to assess end-organ damage

Answer 7

ECG (LVH)
Echo (LVH)
Proteinuria
Renal ultrasound
Renal function

Question 8

Risk factors

Answer 8

Previous MI stroke 
Smoking 
Diabetes Mellitus 
Hypercholesterolaemia 
Renal disease
LVH 
Male

Question 9

What treatable causes should be screened for

Answer 9

Renal artery stenosis
Cushing’s syndromes
Conn’s syndrome
Sleep apnoea

Question 10

First Treatment for under 55yrs

Answer 10

ACE Inhibitor/ARBs - not afrocaribbean or women of child bearing age

If single agent doesn’t control BP, then use two together

If child bearing age: CCB or Beta Blocker

Question 11

First treatment of over 55yrs

Answer 11

CCB and to afrocaribbean of any age

If not suitable offer thiazide (diuretic) - oedema, intolerance, HF

Question 12

Step 2 treatment

Answer 12

Add Diuretic - clortalidone or indapamide

Question 13

Step 3 treatment

Answer 13

Add CCB, ACEi, Diuretic together

Question 14

Step 4 treatment

Answer 14

For resistant HPT:
Low dose diuretic spironolactone (25mg) if K level < 4.5 mmol/l
or
High dose thiazide-like diuretic if K level > 4.5mmol/l

Question 15

Mechanism of ACEi

Answer 15

I.e. Rampiril
Inhibits angiotensin converting enzyme (ACE) which converts angiotensin I -> angiotensin II (vasoconstrictor and hypertrophic agent)

Question 16

Mechanism of CCB

Answer 16

I.e. amlodipine
Blocks L type Ca channels prevent Ca from entering myocytes and blood vessel walls - lower BP

Relax and widen blood vessels by affecting the muscle cells in the arterial walls - reduces TPR

Question 17

List possible complications of HPT

Answer 17

Stroke
LVH
MI
Renal failure

Question 18

Define Stage 1

Answer 18

Clinic BP: 140/90mmHg or higher

ABPM average: 135/85 mmHg or higher

Question 19

Define Stage 2

Answer 19

Clinic BP: 160/100mmHg or higher

ABPM average: 155/95 mmHg or higher

Question 20

Define sever HPT

Answer 20

Clinic systolic 180 mmHg or higher

Clinic diastolic 110 mmHg or higher

Question 21

Control of BP by the sympathetic nervous system

Answer 21

Vasoconstriction
Reflex tachycardia
Increased CO

All increase BP

Question 22

Control of BP by the renin-angiotensin-asdosterone system (RAAS)

Answer 22

Stimulated by :
Low BP (low MAP)
Low circulating volume
Low Na

Released by the juxtaglomerular and converts angiotensinogen to angiotensin I

Angiotensin I to angiotensin II by ACE

Question 23

Why are myocyte and smooth muscle hypertrophy poor prognostic factors?

Answer 23

Hypertrophy makes blood vessels stiff so that they can’t relax which increases bp and if the heart can’t relax, myocytes become ischaemic and start to fibres causing loss of function

Question 24

Action of Angiotensin II

Answer 24

Vasoconstriction
Anti-natriuretic peptide
Stimulator of aldosterone release from the adrenal glands
Hypertrophy of myocytes and smooth muscle

Question 25

Other causes of HPT

Answer 25

Over reactive resistance vessels - increases PVR due to defect in Na transporter of smooth muscle Na effect - if kidneys unable to excrete Na, it builds up in vessels and fluid retained -> high BP

Question 26

Age effect in hypertension

Answer 26

BP rises with age due to decreased arterial compliance

Question 27

Environment effect in HPT

Answer 27

Mental and physical stress increase BP

Question 28

Genetic effect in HPT

Answer 28

FH of HPT common

Question 29

Sodium intake and diet effect in HPT

Answer 29

Reducing salt intake can reduce BP in hypertensive individuals

Question 30

Alcohol effect in HPT

Answer 30

Small amount of alcohol tend to decrease BP Large amounts of alcohol tend to increase BP If alcohol reduced, BP will fall over several days to weeks

Question 31

Weight effect in HPT

Answer 31

Weight reduction is most important non-pharmalogical measure - loss of weight will reduce BP Lower birth weight, higher chance of developing HPT and heart disease

Question 32

Race effect in HPT

Answer 32

Caucasians have lower BP than black population in same environment Rural living has lower BP than in towns Black population genetically salt retainers, so are more sensitive to an increase in diet salt

Question 33

Treatment of Stage 1 HPT

Answer 33

``` Antihypertensive drug to people < 80yrs with ABPM > 135/85 with: Target organ damage CVD Renal disease Diabetes ```

Question 34

Treatment of Stage 2 HPT

Answer 34

Drug treatment to any age with ABPM > 150/95

Question 35

Treatment of > 80yrs

Answer 35

Same drugs as people 55-80yrs, taking into account co-morbidities BP target is different: < 145/85

Question 36

Contraindication to ACEI and drug-drug interactions

Answer 36

Renal artery stenosis Renal failure - NSAIDs Hyperkalaemia - Potassium supplements or potassium sparing diuretics

Question 37

Action of ARB

Answer 37

I.e. losartan, valsartan | Angiotensin II antagonists competitively block the actions of angiotensin II at the angiotensin AT1 receptor

Question 38

What drug do you add if combination of CCB, diuretic and ACEi cause incomplete effect?

Answer 38

Beta blocker

Question 39

HPT in pregnancy

Answer 39

During normal pregnancy, BP falls but if patient has existing HPT it can cause primary HPT -pre-eclampsia Do not treat with ARB or ACEi, use: nifedipine MR, methyl dopa, atenolol then add diuretic and/or amlodipine