12. Hypertension

Question 1

Blood pressure and age

Answer 1

Mean BP rises with age
Systolic rises
Diastolic does not rise
Pulse pressure rises

Question 2

What is the difference between primary and secondary hypertension? Which one is more common?

Answer 2

Primary/ essential: unidentifiable cause (85-95% of cases)

Secondary Hypertension: identifiable cause (5-15%)

Question 3

Name 6 common causes of secondary hypertension

Answer 3

Renal disease
Tumours secreting aldosterone
Tumours secreting catecholamines
Oral contraceptive pill
Pre-eclampsia/ pregnancy 
Genetic causes

Question 4

Aetiology of primary hypertension

Answer 4

Genetics:
Monogenic (rare)
Complex polygenic (common)
Environment:
Dietary salt
Obesity
Alcohol
Pre-natal environment
Pregnancy

Question 5

What monogenic disease causes hypertension?

Answer 5

Liddle’s syndrome

Question 6

5 characteristics of hypertension

Answer 6

Increased TPR
Decreased arterial compliance
Normal cardiac output
Normal blood volume/ ECV
Central shift in volume

Question 7

State 3 causes of elevated TPR in hypertension

Answer 7

Active narrowing of arteries
Structural narrowing of arteries
Capillary loss

Question 8

What is the threshold for hypertension?

Answer 8

140/90 mm Hg

Question 9

What organ has a major influence on hypertension?

Answer 9

Kidneys

hypertension is strongly associated with impaired renal flow and blood flow

Question 10

What is isolated systolic hypertension due to?

Answer 10

Increasing stiffness of medium/large arteries

Question 11

Candidate causes of primary hypertension

Answer 11

Kidney
Endocrine/ paracrine factors
Sympathetic nervous system

Question 12

What do almost all monogenic causes of hypertension affect?

Answer 12

Renal Na+ excretion

Question 13

What risks are increased by high BP?

Answer 13

Coronary heart disease
Stroke
Peripheral vascular disease/atheromatous disease
Heart failure
Atrial fibrillation
Dementia /cognitive impairment 
Retinopathy

Question 14

How is hypertension related to the heart?

Answer 14

Hypertension is associated with an increase in left ventricular wall mass (LVMI) and changes in chamber size

Question 15

What is congestive heart failure?

Answer 15

The inability of the heart to adequately pump blood at normal filling pressures.

Question 16

In how many cases does hypertension precede CHF?

Answer 16

90%

Question 17

What can hypertension do to large arteries?

Answer 17

Arterial hypertrophy
Promote atherosclerosis
Aneurysms (which can lead to thrombosis and haemorrhage)

Question 18

How does hypertension effect the eye?

Answer 18

Affects microvasculature 
Thickening of the wall of small arteries
Arteriolar narrowing
Vasospasm 
Impaired perfusion
Increased leakage into surrounding tissue

Question 19

What does hypertension do to the microvasculature?

Answer 19

Hypertension causes a decrease in capillary density and a subsequent elevation of capillary BP

Question 20

How is the kidney effected in primary hypertension?

Answer 20

Renal dysfunction is common

e.g. increased (micro)albumin excretion in urine

Question 21

How is the kidney effected in accelerated hypertension?

Answer 21

Extreme hypertension is now rare, but leads to rapidly progressive renal failure

Question 22

How does hypertension effect to microalbuminia?

Answer 22

Causes increased albumin loss in the urine
Causes reduced glomerular filtration rate (GFR)
GFR declines with age even without high BP, which speeds up deterioration

Question 23

What are the lifestyle modifications suggested as treatment for hypertension?

Answer 23

Weight loss
Exercise
Eat healthy
Less alcohol

Question 24

What types of drug are used to treat hypertension?

Answer 24

ACE inhibitors

Angiotensin receptor blockers

Question 25

When are loop diuretics used to treat hypertension?

Answer 25

in patients experiencing hypertensive crisis

Question 26

How are thiazide diuretics used to treat hypertension?

Answer 26

Do NOT work through diuresis but because they slowly reduce PVR, mechanism still uncertain

Question 27

How are Beta Blockers used to treat hypertension?

Answer 27

Blockage of β1 receptors in heart:
Reduced rate and force of contraction
Reduced cardiac output

Blockage of β1 receptors in kidney
Reduced secretion of renin
Reduced activity of RAAS

Question 28

How are Calcium channel blockers used to treat hypertension?

Answer 28

Major mechanism: In vascular smooth muscle
Reducing Ca2+ influx reduces actin myosin cross bridge cycling
Minor mechanism: In the heart
Inhibition of Ca2+ influx reduces contractility (negative inotropy) and rate of conduction (negative dromotropy)