1. Essential Hypertension
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2. Hypertension Hypertension is not a disease
It is an arbitrarily defined disorder to which both environmental and genetic factors contribute
Major risk factor for:
cerebrovascular disease
myocardial infarction
heart failure
peripheral vascular disease
renal failure
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3. This left ventricle is very thickened (slightly over 2 cm in thickness), but the rest of the heart is not greatly enlarged. This is typical for hypertensive heart disease. The hypertension creates a greater pressure load on the heart to induce the hypertrophy.
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4. The left ventricle is markedly thickened in this patient with severe hypertension that was untreated for many years. The myocardial fibers have undergone hypertrophy.
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5. The definition of hypertension has been arbitrarily set as:
Blood pressure is a continuous variable which fluctuates widely during the day
physical stress
mental stress
The definition of hypertension has been arbitrarily set as:
That blood pressure above which the benefits of treatment outweigh the risks in term of morbidity and mortality
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6. Blood Pressure Exhibits a normal distribution within the population
Increasing blood pressure is associated with a progressive increase in the risk of stroke and cardiovascular disease
Risk however rises exponentially and not linearly with pressure
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7. At what blood pressure is a patient hypertensive?
BHS 140/90
JNC-VI 140/90 Opt <120/<80
WHO-ISH 140/90
The current recommendation in the UK is 140/90
However risk is important and in diabetes 130/80
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8. In 95% of cases no cause can be found In 5-10% a cause can be found
Chronic renal disease
Renal artery stenosis
Endocrine disease, Cushings, Conn’s Syndrome, Phaeochromocytoma, GRA
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9. Risks of Hypertension The risk of hypertension is considerable
The 4th most common cause of death world-wide
Directly and indirectly responsible for >20% of all deaths
The risks of hypertension have been most thoroughly determined by the Framingham Study - a longitudinal study performed in the USA
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10. Framingham Study
This study clearly demonstrated that the relative risk to a patient with a DBP of 99 mmHg compared to a DBP of 84 mm Hg for
Stroke increases 4 fold
MI increases 2 times
The same was also found to be true for systolic blood pressure
These pressure are common
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11. Despite the clear relationship between blood pressure and morbidity the risk from hypertension also depends on and increases exponentially with other factors
Cigarette smoking Adds 20/10 mmHg
Diabetes mellitus X increase MI
Renal disease
Male 2X risk
Hyperlipidaemia
Previous MI or stroke
Left ventricular hypertrophy 2X risk
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12. Control of blood pressure
Blood pressure is controlled by an integrated system
Prime contributors to blood pressure are:
Cardiac output
Stroke volume
Heart rate
Peripheral vascular resistance
Each of these factors can be manipulated by drug therapy
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13. Sympathetic Nervous System
Sympathetic system activation produces
vasoconstriction
reflex tachycardia
increased cardiac output
In this way blood pressure is increased
The actions of the sympathetic system are rapid and account for second to second blood pressure control
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14. The renin-angiotensin-aldosterone system
The RAAS is pivotal in long-term BP control
The RAAS is responsible for:
maintenance of sodium balance
control of blood volume
control of blood pressure
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15. The RAAS is stimulated by:
fall in BP
fall in circulating volume
sodium depletion
Any of the above stimulate renin release from the juxtaglomerular apparatus
Renin converts angiotensinogen to angiotensin I
Angiotensin I is converted to angiotensin II by angiotensin converting enzyme (ACE)
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16. Angiotensin II is a potent
vasoconstrictor
anti-natriuretic peptide
stimulator of aldosterone release from the adrenal glands
Aldosterone is also a potent antinatriuretic and antidiuretic peptide
Angiotensin II is also a potent hypertrophic agent which stimulates myocyte and smooth muscle hypertrophy in the arterioles
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17. Myocyte and smooth muscle hypertrophy:
are both poor prognostic indicators in patients with hypertension
partially explain why hypertension and the risks of hypertension persist in some patients despite treatment
Both the sympathetic and RAAS are key targets in the treatment of hypertension
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18. Aetiology of essential hypertension
The aetiology of hypertension is
Polygenic
Major genes
Poly genes
Polyfactorial
Environment
Individual and Shared
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19. A sodium homeostatic effect
Likely causes:
Increased reactivity of resistance vessels and resultant increase in peripheral resistance
as a result of an hereditary defect of the smooth muscle lining arterioles
A sodium homeostatic effect
In essential hypertension the kidneys are unable to excrete appropriate amounts of sodium for any given BP. As a result sodium and fluid are retained and the BP increases
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20. Other factors Age Genetics and family history Environment Weight
Alcohol intake
Race
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21. AGE
BP tends to rise with age, possibly as a result of decreased arterial compliance.
Hypertension in the elderly should be treated as aggressively as in the young. They have more to lose
Studies such as EWPHE, Primary Care Study,MRC Hypertension in the Older Adult, SHEP, SYSTEUR and STOP-1 and 2 have proven that treating both diastolic and systolic hypertension in the elderly significantly reduces stoke and MI.
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22. GENETICS A history of hypertension tends to run in families
The closest correlation exists between sibs rather than parent and child
It is also possible that environmental factors common to members of the family also have a role in the development of hypertension
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23. Environment Mental and physical stress both increase blood pressure
However removing stress does nor necessarily return blood pressure to normal values
True stress responders who have very high BP when they attend their doctor but low normal pressures otherwise tend to be highly resistant to treatment
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24. Sodium Intake
The SALT study and more recently the DASH study have confirmed a strong relationship between hypertension, stroke and salt intake
Reducing salt intake in hypertensive individuals does lower blood pressure
However reducing salt intake in normotensives appears to have no effect
Reducing salt intake to <1.5gm/day or better <0.5gm/day does lower BP
However there are real difficulties in achieving this level of salt restriction (fast food)
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25. ALCOHOL The most common cause oh hypertension in the young Scot
Affects 1% of the population
Small amounts of alcohol tend to decrease BP
Large amounts of alcohol tend to increase BP
If alcohol consumption is reduced BP will fall over several days to weeks.
Average fall is small 5/3 mmHg
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26. Weight Obese patients have a higher BP
Up to 30% of hypertension is attributable in part or wholly to obesity
If a patient loses weight BP will fall
In untreated patients a weight loss of 9Kg has been reported to produce a fall in BP of 19/18 mmHg
In treated patients a fall in BP of 30/21 mmHg has been reported
Weight reduction is the most important non-pharmacological measure available
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27. Birth Weight
Birth weight is also associated with the development of hypertension in later life.
The lower the birth weight the higher the likelihood of developing hypertension and heart disease
Clearly in-utero factors affect health at a later stage.
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28. Race
Caucasians have a lower BP than black populations living in the same environment
Black populations living in rural Africa have a lower BP than those living in towns
Reasons are not clear
Possibly black populations are more susceptible to stress when living in towns
Respond in different ways to changes in diet
Black populations are genetically selected to be salt retainers and so are more sensitive to an increase in dietary salt intake
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29. Secondary Hypertension
5-10% of all hypertension has an identifiable cause
Removal of the cause does not guarantee that the hypertension or risk will return to normal
Sustained hypertension produces end-organ damage to blood vessels, heart and kidney
This type of damage tends to increase BP further and so a vicious self-propagating cycle is established
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30. Causes for Secondary Hypertension
Renal disease
20% of resistant hypertensive patients
chronic pyelonephritis
renal artery stenosis
polycystic kidneys
Drug Induced
NSAIDs
Oral contraceptive
Corticosteroids
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31. Pregnancy Endocrine Vascular Sleep Apnoea pre-eclampsia
Conn’s Syndrome
Cushings disease
Phaeochromocytoma
Hypo and hyperthyroidism
Acromegaly
Vascular
Coarctation of the aorta
Sleep Apnoea
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32. The risks of hypertension
The risks of hypertension are well recognised
Cerebrovascular disease
Thromboembolic
Intra cranial bleed
TIA
Cardiovascular disease
Myocardial infarction
Heart failure
Coronary artery disease
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33. The risks of hypertension
Peripheral vascular disease
Renal failure
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34. The risks of hypertension
A sustained increase in BP increases the load on the heart and blood vessels
This has two effects
Myocardial hypertrophy
Smooth muscle hypertrophy in the resistance vessels
Hypertrophy of this type increases the strength of the heart and vasculature
However it also reduces compliance
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35. The effects of reduced compliance are:
A reduction in the ability of the heart to to respond to increased or variable loads
a decrease in the ability of the resistance vessels to relax
For the same level of BP and irrespective of age the presence of left ventricular hypertrophy increases 5 year mortality by
33% in men
21% in women
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36. Atheromatous disease The Heart
Sustained hypertension is associated with accelerated atheromatous disease of the blood vessels
Peripheral vascular disease
Coronary artery disease
Cerebrovascular disease
Renal artery disease
The Heart MI
Heart failure
Angina
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37. Detection and Diagnosis
Initial assessment
History
Office blood pressure
ABPM
Abdominal ultrasound scan
Inpatient assessment
Assess risk
Smoking
Diabetes
Previous pathology
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38. The Aetiology of Hypertension
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Hypertension
Medication for High Blood Pressure
Diuretics
Rid the body of excess fluids and salt
Beta-blockers
Reduce the heart rate and the work of the heart
Calcium antagonists
Reduce heart rate and relax blood vessels
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Clinical Pharmacology Phase II

39. The Aetiology of Hypertension
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Hypertension
Medication for High Blood Pressure
Angiotensin II receptor blockers(ACE)
Interfere with the bodies production of angiotensin, a chemical that causes the arteries to constrict (narrow)
Vasodialators
Cause the muscle in the wall of the blood vessels to relax, allowing the vessel to dialate (widen)
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Clinical Pharmacology Phase II

40. The Aetiology of Hypertension
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Hypertension
Medication for High Blood Pressure
Sympathetic nerve inhibitors
Sympathetic nerves go from the brain to all parts of the body, including the arteries
Cause arteries to constrict raising blood pressure
These drugs reduce blood pressure by inhibiting these nerves from constricting blood vessels
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Clinical Pharmacology Phase II

41. The Aetiology of Hypertension
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Hypertension
Home Blood Pressure Monitoring
Mercury sphygmomanometer
Standard for BP monitoring
No calibration
May be bulky
Need a second person to use machine
May be difficult for hearing impaired or patients with arthritis
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Clinical Pharmacology Phase II

42. The Aetiology of Hypertension
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Hypertension
Home Blood Pressure Monitoring
Aneroid equipment
Inexpensive, lightweight and portable
Two person operation/need stethoscope
Delicate mechanism, easily damaged
Needs calibration with mercury sphygmomanometer
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Clinical Pharmacology Phase II

43. The Aetiology of Hypertension
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Hypertension
Home Blood Pressure Monitoring
Automatic equipment
Contained in one unit
Portable with easy-to-read digital display
Expensive, fragile
Must be calibrated
Requires careful cuff placement
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Clinical Pharmacology Phase II

44. TARGET <140 mm Hg systolic and < 90 mmHg diastolic
Treatment of Adults with Systolic-Diastolic Hypertension without Other Compelling Indications
TARGET <140 mm Hg systolic and < 90 mmHg diastolic
INITIAL TREATMENT AND MONOTHERAPY
Lifestyle modification
therapy
Thiazide
ACE-I
ARB
Long-acting
CCB
Beta- blocker*
* Not indicated as first line therapy over 60
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45. Summary: Treatment of Hypertension without Other Compelling Indications
TARGET <140 mm Hg systolic and < 90 mmHg diastolic
Lifestyle modification
therapy
Thiazide
diuretic
ACE-I
ARB
Long-acting
CCB
Beta- blocker*
CONSIDER
Nonadherence?
Secondary HTN?
Interfering drugs or lifestyle?
White coat effect?
Dual Combination
Triple or Quadruple Therapy
* Not indicated as first line therapy over 60
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46. Thank you for attention!
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