The Cardiovascular System|
Synonyms : High Blood Pressure
is defined as an elevation of systolic and/or diastolic blood pressure above
generally accepted normal level of up to 140/90 mm Hg for adults. However the
average systolic and diastolic blood pressures gradually rise with age and
some allowance has to be made for this when assessing suspected hypertension.
guidelines for diagnosis of elevated
blood pressure in adults (18 years and older) are as follows:
< 120 systolic and <80 diastolic
<130 systolic and <85 diastolic
normal blood pressure
systolic 130-140 or diastolic 85-90
systolic 140-160 or diastolic 90-100
systolic 160-180 or diastolic 100-110
systolic > 180 or diastolic > 110
anxiety, discomfort and unfamiliar surroundings can all lead to a transient
rise in blood pressure, and measurements should be repeated when the patient
is resting and relaxed. For example office or white coat hypertension refers
to blood pressure that is consistently elevated in the physician’s surgery
but normal when measured at home. Patients who have a high blood pressure on
first examination which subsequently settles with rest may not require
treatment but should be kept under review because they are more likely to
develop sustained hypertension. According to the guidelines, some 15% of
general population (25% of adults) can be regarded as hypertensive, though
only a proportion of these will be diagnosed or receive treatment.
about 5-10% of cases, hypertension can be shown to be a consequence of a specific disease or abnormality, such as:
(narrowing) of the aorta, which can be a developmental abnormality or may
occur in Turner’s syndrome in women (congenital chromosomal abnormality
characterised by the absence of one X sex chromosome; therefore the genetic
profile is 45 X0)
disease (chronic glomerulonephritis, chronic pyelonephritis, chronic renal
failure, renal artery stenosis)
phaeochromocytoma (a benign tumour
characterised by hypersecretion of
noradrenaline); the main feature is occasional episodes of palpitations,
tremor, sweating, flushing and throbbing headache
Cushing’s syndrome (hypersecretion of glucocorticosteroids)
Conn’s syndrome (hyperaldosteronism)
acromegaly (hypersecretion of growth hormone)
consumption of alcohol
(oral contraceptives, corticosteroids, anabolic steroids)
the majority of patients with hypertension it is not possible to define a
specific underlying cause, and they are said to have essential
(idiopathic) hypertension. In 70% of such patients another member of the
family is affected (positive family history).
pathogenesis of essential hypertension is not clearly understood. However, it
is known that the underlying defect is increase in peripheral vascular
resistance. Some believe that this is due to increase in sympathetic nervous
activity while others believe that there is a fundamental defect in the
vascular smooth muscle related to abnormal transport of ions across the cell
membrane and increased sensitivity to sympathetic stimulation. Excessive water
and sodium retention by the kidneys and deficiency of vasodilator substances
(e.g., bradykinin) have also been suggested.
Long-standing hypertension causes irreversible changes in peripheral blood vessels in form of arteriolosclerosis (concentric thickening of small arterial blood vessels) when high blood pressure is established permanently. This narrowing of blood vessels causes progressive ischaemia of tissues, which could be responsible for certain complications of hypertension especially in the retina and kidneys.
Clinical features: < BACK TO TOP >
is often referred to as a “silent killer?because most patients initially
remain asymptomatic, and the diagnosis is therefore usually made at routine
headache or polyuria (abnormally large quantities of urine with frequent
urination) appear; however most patients with hypertension do not get
occur in long standing cases giving rise to relevant symptoms:
stroke (a major cause of death in
hypertensive patients) caused by cerebral infarction or haemorrhage
hypertensive encephalopathy, a rare condition
characterised by a very high
that leads to cerebral oedema and serious neurological symptoms such as severe
headache, nausea, vomiting, transient disturbances of speech and vision,
paraesthesiae (tingling), paresis (weakness) of muscles, convulsions and loss
hypertensive retinopathy (progressive irreversible changes in the retina of
the eye causing eventually visual field defects or even blindness)
left ventricular hypertrophy due to increased
cardiac workload and in time left ventricular failure (so called hypertensive
increased incidence of atherosclerosis and
coronary artery disease
proteinuria and progressive chronic renal failure (the most common cause of chronic renal failure is diabetes mellitus, followed by long-standing hypertension)
Diagnosis: < BACK TO TOP >
measurements of the blood pressure are necessary to establish the existence
of hypertension with certainty; at least two blood pressure determinations
should be taken on each of 3 consecutive days before a patient is diagnosed
analysis for proteins (may indicate renal disease) and glucose (diabetes may
coexist and is a risk factor for vascular disease) is routinely carried out;
plasma urea/creatinine and creatinine clearance are measured to assess renal
electrolytes can also provide important clues; hypokalaemic alkalosis may
indicate primary (Conn’s syndrome) or secondary hyperaldosteronism (found
in heart failure, liver cirrhosis and treatment with diuretic drugs).
total cholesterol, LDL and HDL are also ordered because hypercholesterolaemia
is an important risk factor for vascular disease.
X-ray can be used to detect cardiomegaly (enlargement of the heart) or heart
failure; ultrasound can be used to check for cardiac hypertrophy or signs of
weakening of the heart.
can reveal left ventricular hypertrophy (hypertensive heart disease) and
myocardial ischaemia in coronary heart disease.
urine collection for metanephrine or vannylmandelic acid excretion
(adrenaline metabolites) can be done if history suggests phaechromocytoma.
urogram (administration of a contrast medium which is excreted through the
kidney and recording X-ray during this process) may be scheduled if renal
disease is suspected.
Radionuclide renography (similar to urogram but a radionuclide is given and radiation is detected by a gamma camera) is used to assess renal function.
Management < BACK TO TOP >
object of treating systemic arterial hypertension is to reduce the risk of
complications and to improve patient survival.
measures such as reducing alcohol consumption and intake of salt, correcting
obesity, stopping smoking, taking regular exercise, avoiding stress,
relaxation techniques, massage and aromatherapy alone may be sufficient in
certain number of patients.
diuretics (bendrofluazide [Aprinox], hydrochlorothiazide [Diclotride] and
cyclopenthiazide [Navidrex]) are effective but may take up to a month for the
maximum effect to be observed (warning: these drugs may cause reversible male
impotence, and also can worsen type II diabetes and gout).
antagonists (atenolol [Tenormin, Anselol] and metoprolol [Betaloc,
Lopressor]) reduce blood pressure by reducing cardiac output; a1/b-antagonists (e.g., carvedilol [Dilatrend])
work by reducing both cardiac output and peripheral vascular resistance.
converting enzyme (ACE) inhibitors (captopril [Capoten], enalapril [Renitec],
lisinopril [Prinvil], fosinopril [Monopril], ramipril [Tritace, Ramace],
perindopril [Coversyl]) have been a major advance in the treatment of
hypertension (sometimes cause dry cough).
II antagonists (losartan [Cozaar], irbesartan [Avapro] and telmisartan [Pritor,
Micardis]) are the latest addition to antihypertensive treatment (their
advantage over ACE inhibitors is that they don’t cause cough).
antagonists (nifedipine [Adalat, Nifecard], verapamil [Isoptin, Cordilox,
Veracaps], felodipine [Plenidil, Agon] and amlodipine [Norvasc]) are
particularly useful when hypertension coexists with angina.
a1-adrenoceptor antagonists such as prazosin [Minipress, Pressin], doxazosin [Carduran] and terazosin [Hytrin] reduce blood pressure by causing peripheral vasodilation.
Prognosis < BACK TO TOP >
Nutrition < BACK TO TOP >
Nutrition that alleviate or prevent Hypertension :-
Herbs < BACK TO TOP >
Herbs that alleviate or prevent Hypertension :-
(source : -)
15 May 2009
19 June 2005
International Day of Families
Happy Father's Day
Animation Source : Minibyte Solutions
speaker Mr NgThian Watt the Principal Trainer from
Napoleon Hill Associates MalaysiaDetails