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LSS 1- CVS > Hypertension > Flashcards

Flashcards in Hypertension Deck (26):
1

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

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

2

what is hypertension

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

3

What is the threshold for hypertension?

140/90 mm Hg

4

How does blood pressure change with age?

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

5

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

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

6

what is the threshold for BP risk?

There is no reliable threshold for BP risk

7

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

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

8

Give some examples of secondary hypertension.

-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)

9

what is the heritability percentage of high blood pressure?

30-50%.

10

Give some lifestyle risk factors of hypertension.

Obesity, Smoking, Alcohol, Salt Intake

11

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

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

12

In primary hypertension, what causes increased blood pressure?

It is due to elevated peripheral resistence

13

State three causes of an increase in TPR.

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

14

what is isolated systolic hypertension and who does it affect?

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.

15

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

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

16

What is congestive heart failure?

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

17

what are the causes of high blood pressure?

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

18

what can hypertension do to the left ventricles?

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

19

What can hypertension do to large arteries?

Arterial hypertrophy
Promote atherosclerosis
Aneurysms - thrombosis and haemorrhage

Arterial Dilation  ANEURYSM
Arterial Rupture  THROMBOTIC EVENT / STROKE

20

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

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.

21

What does hypertension do to the microvasculature?

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.

22

What is the effect of blood pressure on microalbuminuria?

-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

23

What becomes present in the urine in hypertensive people?

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.

24

what can be used to measure blood pressure?

Blood pressure can be measured using sphygmomanometry on the upper arm

25

summarise the consequences of hypertension?

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

26

what are the treatment options for hypertension?

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