Hypertension

Question 1

What is hypertension associated with and how many does it affect worldwide?

Answer 1

Hypertension affects approximately 1 billion people worldwide and is the leading global cause of death

Question 2

what is hypertension

Answer 2

Hypertension can be defined as the level of blood pressure above which investigation and treatment do more good than harm

Question 3

What is the threshold for hypertension?

Answer 3

140/90 mm Hg

Question 4

How does blood pressure change with age?

Answer 4

Systolic increases fairly linearly
Diastolic plateaus and then decreases
The difference between systolic and diastolic increases

Question 5

what is the relationship between systolic BP and the risk of stroke?

Answer 5

The relationship between BP and risk is exponential (log linear)

Question 6

what is the threshold for BP risk?

Answer 6

There is no reliable threshold for BP risk

Question 7

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

Answer 7

Primary/Essential Hypertension - has no known cause (95% of all hypertension)
Secondary Hypertension - has an underlying cause

Question 8

Give some examples of secondary hypertension.

Answer 8

• Renal disease, including renal artery stenosis,
• Tumours secreting aldosterone (Conn’s syndrome)
• Tumours secreting catecholamines (phaeochromocytoma)
• Oral contraceptive pill
• Pre-eclampsia/pregnancy associated hypertension
• Rare genetic causes (e.g. Liddle’s syndrome)

Question 9

what is the heritability percentage of high blood pressure?

Answer 9

30-50%.

Question 10

Give some lifestyle risk factors of hypertension.

Answer 10

Obesity, Smoking, Alcohol, Salt Intake

Question 11

What part of the CO = MABP/TPR equation is most affected in hypertension?

Answer 11

There is an increase in TPR caused by decreased arterial compliance
Normal cardiac output
Normal blood volume

Question 12

In primary hypertension, what causes increased blood pressure?

Answer 12

It is due to elevated peripheral resistence

Question 13

State three causes of an increase in TPR.

Answer 13

Active narrowing of arteries - vasoconstriction
Structural narrowing of arteries - due to remodelling and growth
Loss of capillaries

Question 14

what is isolated systolic hypertension and who does it affect?

Answer 14

Systolic BP ≥ 140 mmHg, diastolic BP ≤ 90 mmHg

• condition of people over age 60
• Due to increasing stiffness of medium/large arteries
• Pulse wave reflected and is greater by the time it reaches brachial artery
• Does NOT mean that TPR increases.

If the systolic blood pressure is elevated (>140) with a normal (<90) diastolic blood pressure (DBP), it is called “isolated systolic hypertension”

-The pulse wave is reflected- it bounces off the walls of the stiffened blood vessels.

Question 15

What organ has a major influence on hypertension and what are the other possible causes of primary hypertension?

Answer 15

Kidneys - hypertension is strongly associated with impaired renal flow and blood flow.
The kidney exerts a major influence on BP through regulation of sodium/water/extracellular fluid volume.

-sympathetic nervous system:
evidence linking high sympathetic activity with the development of hypertension.
-Endocrine/Paracrine factors

Question 16

What is congestive heart failure?

Answer 16

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

Question 17

what are the causes of high blood pressure?

Answer 17

• coronary heart disease
• stroke
• peripheral vascular disease/atheromatous disease
• heart failure
• atrial fibrillation
• dementia /cognitive impairment
• retinopathy

Question 18

what can hypertension do to the left ventricles?

Answer 18

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

Wall Modelling changes  LEFT VENTRICULAR HYPERTOPHY
3x Increased risk of HEART FAILURE
Hypertension precedes in 90% of Heart Failure cases

Question 19

What can hypertension do to large arteries?

Answer 19

Arterial hypertrophy
Promote atherosclerosis
Aneurysms - thrombosis and haemorrhage

Arterial Dilation  ANEURYSM
Arterial Rupture  THROMBOTIC EVENT / STROKE

Question 20

what are the effects of hypertension on the eye and what consequences does this have?

Answer 20

The retina illustrates microvascular damage in hypertension. There is thickening of the wall of small arteries, arteriolar narrowing, vasospasm, impaired perfusion and increased leakage into the surrounding tissue.
-Blindness or blurred vision caused by retinal microvascular damage.

Question 21

What does hypertension do to the microvasculature?

Answer 21

Hypertension causes a decrease in capillary density: this could lead to impaired perfusion and an increase in peripheral vascular resistance, and a subsequent elevation of capillary blood pressure which leads to damage and leakage.

Question 22

What is the effect of blood pressure on microalbuminuria?

Answer 22

• Hypertension causes increased albumin loss in the urine
• Hypertension causes reduced glomerular filtration rate.
• GFR declines with age even without high BP, which speeds up deterioration

Question 23

What becomes present in the urine in hypertensive people?

Answer 23

The kidneys are a target for damage due to hypertension. It leads to renal dysfunction leading to the presence of albumin in the urine (microalbuminuria). The concentration of albumin in the urine is proportional to the systolic blood pressure.
-Microalbuminuria is a sign of glomerular damage.

Question 24

what can be used to measure blood pressure?

Answer 24

Blood pressure can be measured using sphygmomanometry on the upper arm

Question 25

summarise the consequences of hypertension?

Answer 25

Blindness or blurred vision caused by retinal microvascular damage
Kidney dysfunction caused by high pressure in microvasculature which affects filtration and reabsorption
Stroke caused by damage to vessels in the brain
Heart attack caused by damage to coronary vessels

Question 26

what are the treatment options for hypertension?

Answer 26

ACE Inhibitor e.g. Ramipril
Inhibits Angiotensin II production in lungs and kidneys
If patient develops cough, give ARB (e.g. Losartan) instead

Thiazide Diuretic e.g. Benzoflumethiazide
Act on distal convoluted tubule
Mechanism unknown

Calcium-channel blocker e.g. Amlodipine
VASCULAR SMOOTH MUSCLE: Reduces actin-myosin cross bridge cycling
HEART: Reduces contractility
Vascular effect is the primary mechanism

Beta-Blocker e.g. Propranolol
Blockage of HEART B1 receptors: Reduces contractility and heart rate
Blockage of KIDNEY B1 receptors: Reduced activity of RAAS axis