Hypertension doubles the risk of cardiovascular diseases including coronary heart disease CHD congestive heart failure CHF ischemic and hemorrhagic stroke renal failure and peripheral arterial disease ID: 933846
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Slide1
SYSTEMIC HYPERTENSION
Slide2Hypertension is one of the leading causes of the global burden of disease.
Hypertension
doubles the risk of cardiovascular diseases, including coronary heart disease (CHD), congestive heart failure (CHF), ischemic and hemorrhagic stroke, renal failure, and peripheral arterial disease
.
Although
antihypertensive therapy clearly reduces the risks of cardiovascular and renal disease, large segments of the hypertensive population are either untreated or inadequately treated.
Slide3Definition
Hypertension currently is defined as a usual BP of 140/90 mm Hg or higher, for which the benefits of drug treatment have been definitively established
Slide4Staging of Office Blood Pressure
BP STAGE
SYSTOLIC BP (mm Hg)
DIASTOLIC BP (mm Hg)
Normal
<120
<80
Prehypertension
120-139
80-89
Stage 1 hypertension
140-159
90-99
Stage 2 hypertension
≥160
≥100
Slide5Aetiology
Primary (Essential) hypertension
The majority
(90–95%)
of patients with
hypertension have primary
elevation of blood pressure, i.e. essential
hypertension of
unknown cause
.
Secondary hypertension (5-10%).
Slide6Many factors may contribute
to development of essential HT
Neural
Mechanisms
Baroreflex
control of sinus node function is
abnormal
Obesity-Related
Hypertension
Obstructive Sleep Apnea
Renal
Mechanisms
acquired or inherited defect in the kidneys' ability to excrete the excessive sodium
load
Low Birth
Weight
Genetic Contributions
Slide7Vascular
Mechanisms
Endothelial Cell
Dysfunction
Vascular
Remodeling: An
increase in the medial thickness relative to lumen diameter (increased media-to-lumen ratio) is the hallmark of hypertensive remodeling in small and large arteries
.
Hormonal
Mechanisms
Activation of the renin-angiotensin-aldosterone system (RAAS) is one of the most important mechanisms contributing to endothelial cell dysfunction, vascular remodeling, and hypertension
Slide8Secondary hypertension
Renal diseases
These account for over 80% of the cases of
secondary hypertension
.
The
common causes are:
■ diabetic nephropathy
■ chronic glomerulonephritis
■ adult polycystic disease
■ chronic
tubulointerstitial
nephritis
■
renovascular
disease.
Slide9Endocrine causes
These include:
Conn’s syndrome
Congenital adrenal
hyperplasia
phaeochromocytoma
Cushing’s syndrome
acromegaly
.
Hyperparathyroidism
Primary
hypothyroidism
Thyrotoxicosis
Congenital cardiovascular causes
The major cause is
coarctation
of the aorta
Slide10Drugs:
NSAIDs, oral contraceptives,
steroids,
carbenoxolone
,
liquorice
,
sympathomimetics
and vasopressin
.
Pregnancy (pre-
eclampsia
)
Alcohol
Obesity
Slide11All adults should have blood pressure measured
routinely at
least every 5 years until the age of 80 years
.
Seated
blood pressure
when measured after 5 minutes’ resting with
appropriate cuff
size and arm supported is usually sufficient,
but
standing
blood pressure
should be measured in diabetic
and elderly
subjects to exclude orthostatic hypotension
.
The
cuff should
be deflated at 2 mm/s and the blood pressure
measured to
the nearest 2 mmHg
.
Two consistent blood
pressure measurements
are needed to estimate blood pressure,
and more
are recommended if there is variation in the pressure.
When assessing the cardiovascular risk, the average
blood pressure
at separate visits is more accurate than
measurements taken
at a single visit.
Slide12Assessment
History
Family history, lifestyle (exercise, salt intake, smoking habit) and other risk factors should be recorded.
The patient with mild hypertension is usually asymptomatic.
Higher levels of
blood pressure may be associated with headaches,
epistaxis or
nocturia
.
Attacks of sweating, headaches and palpitations point towards the diagnosis of
phaeochromocytoma
.
Breathlessness
may be present owing
to left
ventricular hypertrophy or cardiac failure
,
symptoms
of peripheral arterial vascular disease
suggest the
diagnosis of
atheromatous
renal artery stenosis
.
Slide13Examination
Findings related to hypertension
Loud A2
S4
Forceful sustained apical impulse (heaving)
Slide14Examination
Secondary causes
: Radio-femoral
delay (
coarctation
of the
aorta),
enlarged kidneys (polycystic kidney disease), abdominal bruits (renal artery stenosis) and the characteristic
facies
and habitus of Cushing's syndrome are all examples of physical signs that may help to identify causes of secondary
hypertension.
Risk factors
: Examination
may also reveal features of important risk factors such as central obesity and
hyperlipidaemia
(tendon
xanthomas
etc.).
Complications:
The
optic fundi are often
abnormal
and
there may be evidence of
generalised
atheroma or specific complications such as aortic aneurysm or peripheral vascular disease.
Slide15Investigations
investigation of all
patients
Urinalysis for blood, protein and glucose
Blood urea, electrolytes and
creatinine
N.B.
Hypokalaemic
alkalosis may indicate primary
hyperaldosteronism
but is usually due to diuretic therapy
Blood glucose
Serum total and HDL cholesterol
12-lead ECG (left ventricular hypertrophy, coronary artery disease)
Slide16investigation of selected patients
Chest X-ray
: to detect cardiomegaly, heart failure,
coarctation
of the aorta
Ambulatory BP recording
: to assess borderline or 'white coat' hypertension
Echocardiogram
: to detect or quantify left ventricular hypertrophy
& for the diagnosis
ofcoactation
of aorta
Renal ultrasound
: to detect possible renal disease
Renal angiography
: to detect or confirm presence of renal artery stenosis
Urinary
catecholamines
: to detect possible
phaeochromocytoma
Urinary cortisol and dexamethasone suppression test
: to detect possible Cushing's syndrome
Plasma renin activity and aldosterone
: to detect possible primary
aldosteronism
Slide17Ambulatory blood pressure monitoring
Indirect automatic blood pressure measurements can
be made
over a 24-hour period using a measuring device
worn by
the patient.
they
are used to confirm the diagnosis
in those
patients with
‘white-coat’ hypertension
, i.e.
blood pressure
is completely normal at all stages
except
during
a clinical consultation
These devices may also be
used to
monitor the response of patients to drug treatment
and, in
particular, can be used to determine the adequacy of
24-hour
control with once-daily
medication
Slide18Ambulatory blood pressure recordings seem to be
better predictors
of cardiovascular risk than clinic measurements.
Analysis of the diurnal variation in blood pressure
suggests that
those
hypertensives
with loss of the usual nocturnal
fall in
blood pressure (‘non-dippers’) have a worse
prognosis than
those who retain this pattern.
Slide19Complications
Slide20Slide21Blood vessels
In larger arteries (> 1 mm in diameter), the internal elastic lamina is thickened, smooth muscle is hypertrophied and fibrous tissue is deposited
.
In
smaller arteries (< 1 mm), hyaline arteriosclerosis
aortic aneurysm and aortic
dissection
Central nervous system
Stroke (due
to cerebral
haemorrhage
or
infarction).
Carotid atheroma and transient
ischaemic
attacks are more common in hypertensive patients.
Subarachnoid
haemorrhage
is also associated with hypertension.
Slide22Hypertensive encephalopathy is a rare condition
characterised
by high BP and neurological symptoms, including transient disturbances of speech or vision,
paraesthesiae
, disorientation, fits and loss of consciousness.
Papilloedema
is common.
Retina
central retinal vein thrombosis
Hypertensive retinopathy
Grade I
Arteriolar thickening, tortuosity and increased reflectiveness ('silver wiring')
Grade 2
Grade 1 plus constriction of veins at arterial crossings ('
arteriovenous
nipping')
Grade 3
Grade 2 plus evidence of retinal
ischaemia
(flame-shaped or blot
haemorrhages
and 'cotton wool' exudates)
Grade 4
papilloedema
Slide23Heart
coronary artery disease.
left
ventricular
hypertrophy
Atrial fibrillation
Diastolic dysfunction
LV failure.
Kidneys
Long-standing hypertension may cause proteinuria and progressive renal
failure
by damaging the renal vasculature.
'Malignant' or 'accelerated' phase hypertension
(Diastole>130
mmgh
)
This rare condition may complicate hypertension of any
aetiology
and is
characterised
by accelerated
microvascular
damage
and by intravascular thrombosis.
The
diagnosis is based on evidence of high BP and rapidly progressive end organ damage, such as
retinopathy
(grade 3 or 4),
renal dysfunction
(especially proteinuria) and/or
hypertensive encephalopathy
.
Left
ventricular failure may occur and, if this is untreated, death occurs within months.