Hypertension

Question 1

Types of hypertension

Answer 1

1. Primary or “essential” - no underlying cause
2. Secondary - other pathology is causing it
3. Malignant - syndrome involving severe elevation of arterial blood pressure, resulting in end-organ damage.

Question 2

Aetiology of HTN

Answer 2

reduced elasticity of large arteries, due to age-related and atherosclerosis-related calcification, and degradation of arterial elastin - predominant form in adults

may also be present in conditions associated with increased cardiac output, such as anaemia, hyperthyroidism and aortic regurgitation.

Question 3

Epidemiology

Answer 3

In 2015, it was reported that high blood pressure affected more than 1 in 4 adults in England (31% of men; 26% of women) – around 13.5 million people and contributed to 75,000 deaths.

Question 4

Systolic vs diastolic pressure importance

Answer 4

Raised systolic pressure is more important than raised diastolic pressure as a risk factor for cardiovascular and renal disease

(Although the risk of cardiovascular disease increases progressively with increasing in either)

Question 5

Complications

Answer 5

Increased risk of morbidity and mortality from all causes
Coronary artery disease
Heart failure
Renal failure
Stroke
Peripheral vascular disease
Hypertensive retinopathy

Question 6

Investigations

Answer 6

Patients with a two measured BP >140/90 should be offered either ambulatory BP monitoring or home blood pressure monitoring

Assess for end organ damage including:
- Urine dip and albumin:creatinine level
- Blood glucose, lipids and renal function
- Fundoscopy for evidence of hypertensive retinopathy
- ECG - look for evidence of LV hypertrophy

Question 7

Classification of HTN

Answer 7

Severity is classified by three stages:

1. Single reading >140/90 mmHg and average ambulatory readings >135/85 mmHg
2. Single reading >160/100 mmHg and average ambulatory readings >150/95 mmHg
3. Single reading with systolic >180 mmHg or diastolic >110 mmHg.

Question 8

Management: modifiable risk factors (5)

Answer 8

Controlling risk factors of cardiovascular disease:

Weight loss
Healthy diet (reduce salt and saturated fats)
Reduce alcohol and caffeine
Reduce stress
Stop smoking

Question 9

Indications to start pharmacological management of essential hypertension

Answer 9

Stage 1 hypertensive patients + <80 years old +
- end organ damage, CVS disease, renal disease, diabetes or 10-year CVS risk >10%

OR

Anyone with Stage 2 hypertension

Question 10

Step 1 of Pharmacological management

Answer 10

1. ACE-inhibitor (e.g. Ramipril) if <=55 years old
2. DHP-Calcium Channel Blocker (e.g. Nefedipine) if

> 55 years old
OR
African or Caribbean ethnicity

• If unable to tolerate ACE-inhibitor then switch to Angiotensin Receptor Blocker (e.g. Candesartan)

Question 11

Step 2 of Pharmacological management

Answer 11

(If maximal dose of Step 1 has failed or not tolerated)

Combine CCB and ACE-I/ARB

Question 12

Step 3 of Pharmacological management

Answer 12

(If maximal doses of Step 2 has failed or not tolerated):

Add thiazide-like diuretic (e.g. Indapamide)

Question 13

Step 4 of Pharmacological management

Answer 13

• If blood potassium <4.5mmol/L then add Spironolactone (K+ sparing)
• If >4.5mmol/L increase thiazide-like diuretic dose (increase in K+ excretion)
• Other options at this point if the potassium is >4.5mmol/L include:
  • Alpha blocker (e.g. Doxacosin)
  • Beta blocker (e.g. Atenolol)
  • Referral to cardiology for further advice

Question 14

Malignant Hypertension features

Answer 14

• Blood pressure ≥180 mm Hg systolic and ≥120 mm Hg diastolic
• Evidence of end-organ damage
  
  • Papilloedema and/or retinal haemorrhages
  • New-onset confusion (encephalophathy)
  • Seizure
  • Chest pain
  • Signs of heart failure
  • Acute kidney injury

Question 15

Malignant Hypertension Management
1. Aim
2. Oral or IV

Answer 15

1st line - CCB e.g. amlodipine or nifedipine PO

1. Aim for controlled drop in blood pressure, to around 160/100mmHg over at least 24 hours.

Uncontrolled drops can lead to ischaemic stroke due to poor cerebral autoregulation and perfusion.

Oral medication is preferred to IV, unless there is encephalopathy, heart failure or aortic dissection.

Question 16

Specific situations in treating hypertension: hypertensive encephalopathy

Answer 16

IV Labetalol or IV infusion Sodium Nitroprusside

Question 17

Specific situations in treating hypertension: aortic dissection

Answer 17

IV Labetalol or IV infusion Sodium Nitroprusside, target 100-120mmHg systolic.

Question 18

Specific situations in treating hypertension: pulmonary oedema

Answer 18

IV infusion GTN or Sodium Nitroprusside.
Beta blocker not recommended

Question 19

Specific situations in treating hypertension: pregnancy-induced (pre-eclampsia)

Answer 19

IV Magnesium Sulphate with IV Labetalol/Hydralazine/Methyldopa.

Question 20

Specific situations in treating hypertension: Phaeochromocytoma

Answer 20

IV Phentolamine/Phenoxybenzamine (α blockers) before beta blockade

Question 21

Define secondary hypertension

Answer 21

Some common and uncommon medical conditions can increase blood pressure, leading to secondary hypertension

Question 22

Clinical suspicion of secondary hypertension

Answer 22

• Younger patients with few comorbidities.
• Severe hypertension or hypertension resistant to treatment
• New hypertension in patients with previously stable or low readings.
• Hypertension with associated symptoms or electrolyte disturbances

Question 23

Causes of secondary hypertension… (don’t memorise all of these please)

Answer 23

M/C: Primary intrinsic kidney disease (most common)
Renovascular disease (second most common) - RAS

Kidney
-Glomerulonephritis
-Chronic pyelonephritis
-Polycystic kidney disease
-Atheromatous renal artery stenosis in older co-morbid patients

Fibromuscular dysplasia in a younger patient group

Coarctation of the aorta is a potential cause of secondary hypertension in young children and adolescents.

Endocrine disease
- Cushing’s syndrome (raised cortisol)
- Conn’s syndrome(raised aldosterone)
- Phaeochromocytoma (catecholamine producing tumour)

Question 24

Investigations in 2ndary HTN
1. Hypernatremia and hypokalaemia + raised aldosterone:renin ratio
2. Raised urea and creatinine
3. Raised 24 hour urinary cortisol or dexamethasone suppression test
4. Raised 24 hour metanephrine collection
5. Why renal ultrasound?
6. Why CT/MR angio
7. Why renal biopsy

Answer 24

Renal function (sodium, potassium, urea, creatinine)
1. Conn’s syndrome
2. intrinsic renal disease
3. in Cushing’s syndrome
4. pheochromocytoma
5. looking for evidence of kidney abnormalities (e.g. polycystic kidneys)
6. renovascular disease
7. intrinsic kidney disease