L16 - Hypertension Flashcards by Jack Corston

How many deaths per year in the US due to hypertension

One million

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How does BP vary with age

Increases

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How does BP vary with gender, what causes this?

Higher in males - due to presence of testosterone

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Normal diastolic pressure

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What would be considered a high normal diastolic pressure

85-89

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What would be considered mild hypertension as a diastolic pressure

90-104

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What would be considered moderate hypetension as a diastolic pressure

105-114

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What diastolic pressure would be considered severe hypertension

Greater than 114

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What systolic pressure would be considered normal

140 or below

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What systolic pressure/s would be considered to be borderline systolic hypertension

140-159

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What systolic pressure/s would be considered to be isolated systolic hypertension

Greater than 160

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What do more recent BP guidelines suggest

BP should be kept as low as possible - but so that perfusion throughout the body can be maintained

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What are the two types of hypertension

Essential hypertension

Secondary hypertension

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Essential hypertnesion

Many risk factors but no clear cause

Can be spontaneous

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Secondary hypertension

Consequence of a clinical condition

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MABP is proportional to

CO x TPR

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How does CO vary with age?

Why is this the case

Decreases

The heart is a mechanical pump - this will have a finite number of beats

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How does TPR vary with age

Give examples of what causes this variation

Increases

Arteriosclerosis - stiffening of the vessels

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What are the likely causes of essential hypertension

Cardiac dysfunction
Vessel abnormalities
Kidney dysfunction

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Explain how kidney dysfunction could lead to essential hypertension

In the long term - unable to control total blood volume
Kidneys will naturally vary with age
Known as volume induced hypertnesion

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Explain how cardiac dysfunction could lead to essential hypertension

Increased repsonse to stress and catecholamines, also increase sensitivity to cortisol
Leads to vessel constriction

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What sorts of vessel abnormalities may lead to essential hypertension

Sympathetic NS abnormalities
Abnormalities of local factors
Smooth muscle hypertrophy

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How may smooth muscle hypertrophy lead to EH - what is the name given for the process

Smooth muscle is made to work harder
Any further contractions will be more powerful - causing greater constriction
Leads to VASCULAR REMODELLING

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Why is hypertension classed as a syndrome

Syndrome due to being caused by many different factors

EH is

Familial

Is EH genetic - evidence

Corrleation between twin studies

What races are of an increased EH risk

African-Caribbean

What are some known environmental risk factors for EH

Diet and obesity (metabilic syndrome) Adopting a western lifestyle Salt intake Vit D deff syndrome

What is metabolic syndrome

Collection of symptoms which can lead to type 2 diabetes mellitus

What % of the population has a predisposition to Eh

30-50%

What are the common polymorphisms that contribute to EH

``` Angiotensinogen ENaC (epithelial Na channel) ```

What converts angiotensionogen to angiotensin I

Renin

What converts angiotensin I to angiotensin II

ACE

What is the 'case against salt'

In human studies reduction of salt by 3g/day leads to reduced MABP of 5 mmHg This is equivilant to drug therapy which reduces strokes

What was the problem with low salt (KCl)

Must be reduction in NaCl

What does aldosterone bind to what is its effect

Binds to mineralocorticoid R | Increases the reabsorpiton of Na

What are three potential causes of secondary hypertension

Renal disease Renal artery stenosis Hormone inbalance

How might renal disease lead to secondary hypertension

Nephron fucntion imparied Blood volume and BP increases More damage and kidney failure Viscious circle

How might renal artery stenosis lead to secondary hypertension

Narrowing of the arteries Caused by atheroscleosis Increased renin production and increased BP

How might a hormone imbalance lead to secondary hypertension

Aldosterone increased the NA reabsorption leads to inc BP | If mini adrenal tumours ==> would change ammount of aldosterone produced

What is ateriosclerosis

Arteries become less compliant with age - vascular remodelling

What is arteriosclerosis

Deposition of cholesterol plaques reduced the diameter of the lumen

Symptoms of secondary hypertension

FLusing, sweating and blurred vission USUALLY A-SYMPTOMATIC Arterio/atherosclerosis

What is an aeurysm | Where is a common place for them to occur

Balooning of the arteries | Descending aorta

What are the typical sizes of arteries

2.5-8cm

Why can strokes present as a consequence of secondary hypertension

At high systolic pressure could burst the arteiries which enter the brain

Describe how necrotic tissue which has undergone infarction would be recognised How would this interfere with the normal conduction of the heart

Would interfere with the conducting systems of the heart

How can retinal damage be used to diagnose secondary hypertension

``` Eye is the only place where blood vessels can be seen non invasively Small haemhorrages (spots) of hard and soft exudates would be indicative of hypertension ```

Give some non pharmacological treatments for secondary hypertension

``` Weight loss Diet (decrease in salt alcohol and caffine) Exercise Stopping Smoking Relaxation ```

What classes of drug may be used to treat secondary hypertension

Diuretics Sympatholytics Ca channel blockers Drugs which interfere with the RAA sysytem

RAA system

Renin - angiotensin - aldosterone

Explain how diuretics may be used to treat secondary hypertension

Thiazdes would increase secretion of Na and Cl lowering the total blood volume

Explain how sympatholytics (two classes) may be used to treat secondary hypertension

Alpha blockers Clonidine - decrease sympathetic outflow to reduce the vascular tone Prazoin - relaxes the smooth muscle to cause a fall in TPR Beta blockers Propanolol - To decrease HR and decrease contractility

Describe how Ca channel blockers (BROAD SPECTRUM) may be used to treat secondary hypertension

Minoxidal | Decreases the contractility and the vascular tone

What is another use for minoxidal

Topical application for hair growth

Describe how selective Ca blockers may be used to treat hypertension

Manidipine | Relaxation of the vascualr smooth muscle H

How may ACE inhibitors be used to treat hypertension

E.g. moexipril Inhibition of vascular remodelling Prevention of the proliferation of the cells of the smooth muscle

Unwanted side effect of using ACE inhibitors

Bradykinin cough

Aside from ACE inhibitors what is a common treatment for secondary hypertension

AGII receptor blockers