Pathology of hypertension
As blood pressure increases, peripheral resistance to increased plasma volume tends to decrease until the kidneys fail to increase the volume of fluid in the blood, which can increase resulting in edema.
Hypertension is a symptom of many diseases, many causes but can be one disease, high blood pressure if no cause is found. In the European countries - North America, the rate of hypertension in the population accounts for 15-20% in adults. Specifically, as follows: Benin 14% - Thailand: 6.8% - Zaire: 14% - Chile: 19-21%, Portuguese: 30%, the United States: 6-8%. Overall, very variable rates.
The World Hypertension Organization and the United States National Commission (1997) agree that an adult has hypertension when the systolic pressure is above or equal to 140mmHg and either the diastolic pressure is above or equal to 90mmHg.
This definition is simple but has the disadvantage that the blood pressure reading is not completely stable and the blood pressure changes with age, sex.
Accounting for nearly 90% of cases of hypertension (according to Gifford - Weiss).
Kidney disease: Acute glomerulonephritis, bilateral glomerulonephritis due to multipurpose kidney acquisition, pyelonephritis water retention, kidney tumors cause tearing secretion, renal artery stenosis...
Adrenocortical disease, Cushing's syndrome, Conn's syndrome, tumor overproduction of other corticosteroids (Corticosterone, desoxycortisone), false corticosteroid biosynthesis.
Adrenal medullary disease, adrenal myeloma (Pheochromocytoma).
Cardiovascular disease: Aortic stenosis disease, abdominal aortic stenosis for renal artery, open aortic valve.
Medications: Contraceptive hormones, licorice, carbenoxolone, ACTH Corticoides, Cyclosporine, anorexia, IMAOs, cyclic antidepressants.
Other causes: Hyperthyroidism, Beri-beri disease. Paget bone disease, polycythaemia vera, carcinoid syndrome, respiratory acidosis, cranial hypertension...
Considered to be associated with primary hypertension, although it is still debated:
Genetic factors, familial hypertension.
Eating factors, eating a lot of salt, eating less protide, drinking a lot of alcohol, drinking soft water less Ca ++, Mg ++, and K +. The most prominent and recognized is the relationship between Na + ions and the incidence of hypertension. Na + ions increase blood pressure mediated increase blood volume and especially through the constriction of blood vessels.
Psychosocial factor, having stress frequently.
Pathogenesis of primary hypertension
Arterial hypertension is often accompanied by pathophysiological changes involving the sympathetic nervous system, kidneys, renin-angiotensin and other hemodynamic and humoral mechanisms.
Changes in blood clotting
The heart rate increases, the cardiac output increases, the first period has vasoconstriction to redistribute the circulating blood from the periphery to the heart and lungs, so the resistance of blood vessels also increases. The heart exhibits an increase in compensatory activity and leads to left ventricular thickening. Blood pressure and total peripheral resistance gradually increased. Cardiac flow and systolic flow decrease further, eventually leading to heart failure.
In changes in blood clotting, the artery system is often completely damaged early. In the past, it was thought that only the arterioles were vasoconstrictive, resulting in increased peripheral resistance. Currently, large blood vessels have also been found to play a role in hemodynamics in hypertension. The lesser-known function of large arteries is to reduce impulses and blood flow squeezed by the heart. Consequently, the compliance artérielle parameter indicates well the capacity of the arteries. This decrease shows the stiffness of the large arteries, is a progression of increased blood pressure on the arteries, and in the long run will increase the heart work leading to left ventricular hypertrophy. At the same time, an increase in artery hyperpulsatilité leads to damage of bioelastomeres of the arterial wall.
In the kidneys, increased renal vascular resistance, decreased renal blood flow, renal function decreased, although, in the first time, the glomerular filtration rate and general activity of the kidneys remained.
In the brain, the flow remains balanced within a certain limit during periods of marked hypertension.
As blood pressure increases, peripheral resistance to increased plasma volume tends to decrease until the kidneys fail to increase the volume of fluid in the blood, which can increase resulting in edema.
In the early stages, the sympathetic effect manifests itself in an increase in cardiac rate and an increase in cardiac output. The sympathetic nervous system activity is also expressed in the amount of Catecholamine in plasma and cerebrospinal fluid such as adrenaline, no- adrenaline, but the concentration of these substances is also very variable in hypertension.
The sympathomimetic auto-nervous system is controlled by the cerebrospinal-mediated central nervous system and the two are mediated by pressure receptors.
In hypertension, the pressure receptors are regulated to the highest level and with the highest sensitivity threshold.
Changes in humour
Renin-Angiotensin-Aldosterone System (RAA): It has now been shown to have an important role because, in addition to its peripheral effects, it also has a central effect in the brain, causing hypertension through angiotensin II receptors (UNGER-1981, M). PINT, 1982). There is an author dividing primary hypertension based on high, low renin plasma concentrations, and there is an inverse relationship between the renin-angiotensin II plasma concentration and age.
Angiotensin II is synthesized from angiotensinogen in the liver and under the effect of renin will form angiotensin I and then converted to angiotensin II is a very strong vasoconstrictor and increases aldosterone secretion. Renin release is controlled through three factors: - Renal perfusion pressure - the amount of Na + coming from the distal tubule and the sympathetic nervous system. The investigation of the RAA system, based on direct or indirect plasma renin or immunological response and angiotensin II quantification, is preferably through ACE inhibitors.
Vasopressin (ADH): has a fairly clear role in the pathogenesis of hypertension with a central effect on blood pressure reduction (mediated by increased CNS susceptibility to the pressure reflex from the carotid artery sinus). and the aortic loops) peripheral vasoconstriction (direct and through activation of Adrenergic fibers) (JF Liard, 1982. B. Bohns, 1982).
Prostaglandins: central effect on blood pressure, peripheral effects to reduce blood pressure (FH UNGER, 1981; MA Petty, 1982).
There is also the role of the Kalli-Krein Kinin (KKK) system in hypertension and some systems with unknown roles such as the Angiotensin system in the brain and the encephalin, the dopamine system that changes the pressure receptor activity. . A regulatory mechanism involving central and peripheral Imidazolique receptors has been documented since the 1980s with the emergence of a blood pressure drug acting on the Imidazole receptor causing vasodilation.
The pathogenesis of secondary hypertension: Depends on the cause of the disease.
Most people with high blood pressure have no symptoms until the disease is discovered. Occipital headache is a common symptom. Other symptoms that may be encountered are mediocre, nervousness, fatigue, difficulty breathing, blurred vision ... Nonspecific. Some other symptoms of high blood pressure depend on the cause of hypertension or the complications of high blood pressure.
Blood pressure measurement: This is an important action; it is necessary to ensure some regulations.
The armband must cover 2/3 of the arm length, the lower margin of the bandage is 2cm above the elbow. If using a mercury gauge, if using a spring type, it must be adjusted every 6 months.
When measuring, need to start the circuit first. Should pump to about 30mmHg above the pressure has lost the circuit (usually over 200mmHg) deflate quickly, record the pressure when the circuit reappears, deflate all. Place the stethoscope on the arm artery, quickly inflate the cuff to 30mmHg above the recorded pressure, slowly discharge at 2mmHg for 1 second (or per beat). Diastolic blood pressure should be selected at the time of pulse loss (phase V Korotkoff). In children and pregnant women should choose phase IV Korotkoff.
If taking the second measurement, wait 30 seconds. If arrhythmia must be re-measured 3 times and take the average of the values.
Blood pressure must be measured several times, in 5 consecutive days. Measure blood pressure in both upper and lower extremities, both lying and standing. Usually, choose left-hand blood pressure as the standard.
The patient may be obese, round-faced in Cushing's syndrome, and the upper extremities are more developed than the lower extremities in aortic stenosis. Look for atherosclerotic manifestations of the skin (maculoma, adipoma, corneal arch ..).
A cardiovascular examination can detect early left ventricular thickening or heart failure, the intercostal artery beats in the aortic stenosis. Touch and listen to the artery to detect blockage or blockage of the carotid artery in the abdominal aorta ...
It should be noted that the phenomenon (false blood pressure) in the elderly with diabetes, renal failure due to the hardening of the arteries makes the measured blood pressure higher than the value of intravascular pressure. It can be eliminated by using the Osler "procedure" or, most accurately, direct blood pressure measurement. Another phenomenon that is also trying to eliminate is the "white robe" effect using the Holter tensional method.
Abdominal examination may detect bilateral umbilical systolic murmur in renal artery stenosis, bulging aorta or detect enlarged kidney, polycystic kidney.
A neurological examination can detect old or mild cerebral vascular complications.
Needs simple, purposeful to assess cardiovascular risk, kidney damage and find the cause.
Minimum Billan (according to the World Health Organization):
Blood: Blood Potassium, Blood Créatinine, Blood Cholesterol, Blood Sugar, Haematocrit, Blood Uric Acid. Urine: Red blood cells, Protein.
If possible, should do a more, fundoscopy, electrocardiogram, heart X-ray, ultrasound ...
For secondary hypertension or difficult to determine hypertension, for example, Renal vascular disease: rapid U, I, V scan needed kidney chart, Saralasin test. pheochromocytoma: Catecholamine urine quantification for 24 hours, Régitine test.
Implementing the quadrants
Need early and correct diagnosis of hypertension. Mainly by measuring blood pressure in accordance with the above-mentioned regulations. However, it is important to organize physical examinations to do a thorough examination to detect potential or asymptomatic cases early.
Diagnosis the stage of hypertension
There are two ways of staging, in which the World Health Organization staging is more detailed and appropriate.
According to the World Health Organization (1996) divided into 3 phases:
Stage I: True hypertension without any physical damage.
Stage II: At least one of the following changes:
Left ventricular thickening: Clinical findings, X-ray, electrocardiogram, ultrasound.
Diffuse stenosis or regional retinal arteries (fundus stages I and II by Keith-Wagener-Baker).
Kidney: Microalbumin urine, Proteinuria, urea, or blood creatinine increased slightly. (1.2-2 mg%).
There is an image of atherosclerosis on ultrasound or x-ray (in the aorta, carotid, pelvic, or femoral artery)
Stage III: Signs of function and entity due to damage to target organs:
Heart: Heart failure, angina, myocardial infarction.
Cerebral: Transient cerebral vascular accident, cerebral hemorrhage, cerebellum, or brain stem. Encephalopathy with high blood pressure. Vascular dementia (vascular dementia)
Bottom of the eye: Retinal hemorrhage with or without papillary edema (stages III and IV) These signs are characteristic of malignancy (rapid progression).
Other manifestations are common in stage III, but not very specific for hypertension.
Kidney: plasma creatinine increased (> 2mg%), renal failure.
Vascular: Splitting, blocking arteries, obstructing peripheral arteries with obvious symptoms.
Malignant or rapidly progressive hypertension is a syndrome that includes:
The minimum blood pressure is very high above 130mmHg.
Stage III and IV bottlenecks according to Keith-Weigener.
There are complications in the kidneys, heart, brain.
Young patient under 40.
Rapid progression, death within 2-3 years.
Classification of HA in adults ≥ 18 years (JNC VII, 2003)
Systolic BP (mmHg)
Diastolic BP (mmHg)
THA stage 1
THA stage 2
120 - 139
140 – 159
80 – 90
90 - 99
Classification of hypertension
According to the properties
Frequent hypertension: benign hypertension and malignant hypertension.
High blood pressure fluctuates, sometimes high blood pressure, sometimes normal.
According to the cause
Primary (idiopathic) hypertension.
Progression and complications
Heart failure and coronary artery diseases are the two main complications and the highest cause of death in high blood pressure. Left ventricular thickening is an early complication due to the thickening of the left heart muscle. To deal with peripheral resistance, increasing contractile strength increases cardiac work and thickens the myocardial wall. Gradually heart failure and with exertion dyspnoea, cardiac asthma or acute pulmonary edema followed by total heart failure with edema, hepatomegaly, and venous floating. X-ray and electrocardiogram showed signs of right ventricular thickening.
Coronary artery failure manifests itself as typical angina or arrhythmia. Electrocardiogram with ST depression below the electric line in the left lead leads, more clearly in the Pescador lead when complications of infarction will appear necrotic Q waves.
Stroke, commonly as cerebral palsy, cerebral hemorrhage, transient cerebral stroke with focal neurological symptoms lasting only, not more than 24 hours, or encephalopathy caused by hypertension with confusion, coma according to seizures, vomiting, severe headache.
Early and rapid renal artery atherosclerosis.
Kidney fibrosis causes progressive kidney failure.
Renal arterial fibrous necrosis causes malignant hypertension.
The late stage of severe renal ischemia leads to concentrations of Renin and angiotensin II in the blood causing secondary hyperaldosteronism.
Hypertension is a factor that produces atherosclerosis, which facilitates the formation of atherosclerosis.
Aortic bulging, dissection. Rarely, but a very serious illness can easily lead to death.
Eyes: A fundus exam is very important because it's a good sign of prognosis. According to Keith- Wagener-Barker there are 4 stages of fundus injury.
Stage 1: Hard and shiny arterioles.
Stage 2: Narrow arterioles have a cross (Gunn's mark).
Stage 3: Retinal hemorrhage and secretion.
Stage 4: oedema diffuse papillae.
The principles of treatment
Return blood pressure to a stable physiological value.
Improvement of abnormal changes in large arteries.
Therefore, 3 problems must be solved:
Treatment of the causes of hypertension; Removal of adrenal myeloma, resection of atrophic kidneys, unclogged arteries
Symptomatic treatment of hypertension: With no medical methods or medications or surgery (for example, removal of some sympathetic nerves).
Treatment of complications of hypertension: The general goal of treatment is to return blood pressure to normal values or below 140 / 90mmHg. Respect the physiological blood pressure of the elderly.
General Principle: It should be continuous, simple, economical, and followed closely.
Eating and living
Limit salt to less than 5gNaCl per day, limit fat, animal fats, alcohol, tobacco, and tea. Avoid strenuous mental labor, excessive anxiety, light exercise, relaxing walking, swimming.
It is necessary to master the mechanism of action, the combined effects of drugs to treat hypertension and its side effects when used in the immediate and long term. There are 3 main groups of drugs:
Thiazides and derivatives:
Inhibit the reuptake of Na + and Cl- in distal tubules such as Hydrochlorothiazide (Hypo thiazide) ... 25mg tablet, take 2 capsules a day. Chlorothiazide 500mg tablets, taken 2 capsules/day, are widely used in hypertension. There are also Chlorthalidone (Hygroton) tablets 50mg-100mg x 1 time / day and Metolazone (Diulo) 2.5mg-5mg x 4 times / day or every 2 days because of long-lasting effects.
Thiazide side effects: Increased uric acid, blood boosting, hypokalaemia, diuretic Thiazides less effective when glomerular filtration rate below 25ml / min, increase LDL cholesterol and lower HLD cholesterol.
Loop Diuretics Henlé:
Also lowers blood potassium, but different from the thiazide group is fast and short-acting, depending on the dose.Furosemide (Lasix) tablets 40mg x 1-2vs / day are indicated for severe renal failure, acute hypertension attacks. but in the long term, the effect is not better than the Hypo thiazide group. Other types in the group include Edecrine (Acid ethacrynic), Burinex (Buténamide). Side effects are similar to thiazide but high doses are toxic to the ears.
Potassium distal diuretic includes 2 subgroups:
Aldosterone resistance group such as Spironolactone (Aldactone) tablets 25-50mg x 4 times/day. Canrénone (Phanurane) is effective in cases of hyperaldosteronism, often using a combination of thiazide.
The second group is the group with direct effects such as Amiloride (Modamide), Triamterene (Teriam), this type often has to coordinate with other groups because of the weak Na excretion effect. Side effects: male breasts, menstrual impotence.
Can avoid hypokalaemia in the blood, this type combines an Aldosterone and a thiazides such as Aldactazine, Moduretic, Ditériam ..
Sympathomimetic block type β:
Renin inhibitory effect, reducing heart muscle, reducing central sympathetic nerve activity, has many groups. Cardiac selectivity, cardiac selectivity, and the type with or without intrinsic sympathomimetic effect. Commonly, there is propranolol (Avlocardyl, Inderal) which is non-selective, has no intrinsic sympathomimetic effect (ASI) of 40mg tablets, taking 1 6 tablets/day. Side effects: Slow heart rate, atrioventricular conduction disturbances, aggravation of heart failure, bronchospasm, asthma, Raynaud's syndrome, hypoglycemia, gastrointestinal disturbances, insomnia, allergies or rebound effects when stopping treatment (causing angina, acute myocardial infarction).
Increases the formation of angiotensin II, in addition also works:
Increases activity of the Potassium-Kréine-Kinine system prevents the breakdown of bradykinin.
Stimulates Prostaglandin synthesis. This ultimately leads to vasodilation.
Indication: Stages of hypertension, including high and low rénine hypertension. Side effects: Few side effects other than appetite disturbances, pruritus, dry cough, pay attention to the combination of potassium diuretics, anti-inflammatory drugs, and anti-steroids.
Contraindications: When hypertension has bilateral renal artery stenosis or only one, pregnant women.
There are 3 main groups:
Captopril (Lopril, Captolane) 25-50mg tablet 50mg / day.
Enalapril (Renitec) tablet 5-20mg, dose 20mg / day.
Lisinopril (Prinivil, Zestril) tablets 5-20mg, dose 20mg / day.
The last two groups with long-lasting effects and no Thiol group with fewer side effects should be preferred.
Prevents cell entry of Ca ++ ions. Potentially dependent Ca ++ slow flow of Ca ++ channel. This effect is proportional to the concentration and regression in the presence of calcium ions. There are two places that work.
On the blood vessels: The decrease in the flow of Ca ++ leads to muscle dilation and vasodilation. This reduces peripheral resistance and improves the dilation of large blood vessels.
Cardiac: Slowing the heart rate more or less balancing the secondary tachycardia reflex and reducing myocardial contractility.
These effects depend on the type of Ca ++ inhibitor used. Type 1-4 dihydropyridine has a strong selective effect on blood vessels, while Verapamil and Diltiazem act in both areas. Types of Ca ++ inhibitors work well for low renin hypertension (the elderly) in particular:
Group 1-4 Dihydropyridine: Nifedipine (Adalate) 10mg-20mg LP capsules, dose of 2 capsules / day.
Diltiazem (Tildiem) 300mg LP, dose of 1 tablet / day.
Verapamil (Isoptine) 120-240 LP, 1-2 tablets / day.
Side effects account for 10-20% of cases. Usually headaches, peripheral edema, facial flushing. Rarely are orthostatic hypotension, fatigue, mediocrity, gastrointestinal disturbances, anxiety, rash, drowsiness, and impotence. Types Verapamil, Diltiazem can cause atrial conduction disturbances, bradycardia. Do not use inhibition of calcium during pregnancy, Verapamil and Diltiazem not use in case of heart failure, severe atrioventricular block but not a pacemaker.
The drug acts on the central nervous system:
There are many types, but nowadays they are rarely used due to their many effective side effects.
Anphamethyldopa (Aldomel, Dopegyt): Lower blood pressure by producing alpha- methyladenine activates sympathetic receptors in the brain, thereby inhibiting sympathetic tone. 250mg or 500mg tablets, 500mg to 1.5g dose in 24 hours. Used in the presence of renal failure. Side effects: orthostatic hypotension, hemolytic anemia, impotence, liver failure.
Reserpine tablets 0.25mg dose 2-6 tablets / day. Side effects of orthostatic hypotension, hemolytic anemia, impotence, liver failure, currently rarely used.
Clonidine (Catapressan): Effects on the medulla region with a hypotensive sympathetic tone. 0.150mg tablet dose of 3-6 tablets / day. It should be noted to stop the drug slowly or else it will cause blood pressure to skyrocket. Side effects: Depression dry mouth, constipation, sexual disturbances.
Other centrally acting drugs: Guanabenz, Guanfacine, Tolonidine, Hyperium.
Prazosin (Minipres): The effect of inhibiting alpha receptors after conjugation should have a good effect. Tablets 1mg use increasing dose from 1-2 tablets - 10 tablets / day if needed. Side effects: dizziness, irritable digestive disorders, dysuria, orthostatic hypotension, especially with the first dose.
Dihydralazine (Nepressol) 25mg tablet, the dose from 1-4 tablets/day. Used in the presence of kidney failure, has many side effects. Tachycardia, water-salt retention, erythema pseudo-lupus syndrome, peripheral polyneuritis are not used in the presence of coronary failure, dissected aortic swelling, often indicated in hypertension with renal failure.
Minoxidil (Loniten) very strong effect, only used when resistant to other types of blood pressure, chronic kidney failure; seldom used today.
Assessment of hypertension by risk level by the World Health Organization and the World Hypertension Society (ISH) in 2003.
Follow these steps:
Evaluate factors that influence prognosis, including:
Risk factors for cardiovascular disease:
Systolic and diastolic blood pressure level (grades 1-3).
Male > 55 years old.
Female> 65 years old.
Total cholesterol> 250mg%.
Family history of heart disease.
Other factors that adversely affect prognosis:
Microscopic albumin urinary in diabetics.
Glucose tolerance disorder.
Fibrinogen increased blood.
High socio-economic group.
High-risk ethnic groups.
High-risk geographic area.
Damage to target organs: As in phase II of hypertension according to the World Health Organization's classification before, including: left ventricular thickening, fundus lesions, proteinuria, ...
Accompanying clinical status: as in phase III according to medical institution's rating
The world formerly includes left heart failure, coronary failure, kidney failure, cerebral circulatory failure.
Risk classification helps prognosis:
For low- and moderate-risk hypertension, time should be monitored, then re-evaluated blood pressure and risk factors, and take non-pharmacological measures. For high-risk and very high-risk groups, immediate drug treatment in combination with non-drug therapy is required.
Apply an individualized treatment regimen. It can be summarized in the diagram below (next page):
In the treatment of 2 drugs, the second choice is still in the 4 drug groups step 1. If it fails, after considering the resistance to treatment, the dose is not appropriate ... then it can be considered. to the addition of a third type such as vasodilators or central anti-adrenergic types
Selective indication of the drug according to the approach of individual patient treatment (of the National Council of Hypertension of the American Heart Association JNC VI 1999).
Diuretics: Elderly, black, premenopausal women, kidney parenchymal disorders.
Beta-blockers: Young, Caucasian, men with sympathomimetics, high renin activity, coronary artery disease, glaucoma and migraine patients.
ACE inhibitors: Severe hypertension, resistance to treatment, high renin activity, heart failure or kidney failure, sexual dysfunction, hyperlipidaemia, diabetes mellitus, hyperuricemia.
Calcium inhibitors: the elderly, black skin, coronary artery disease, diabetes. Uncontrolled hypertensive obesity with secondary beta-blocker after primary aldosteronism, impotence, hyperlipidemia, and hyperuricemia.
Peripheral adrenergic resistance: Patients with depression, asthma, obstructive pulmonary disease, diabetes hyperlipidemia.
Treatment without medication
Adjust risk factors.
Treatment of an acute attack of high blood pressure
Need to use a type of hypotension by intravenous route as:
An intravenous nitro prussiate de Na (Nipride) dose of 0.5-2 mg/min (10 mg/hr) is selected for use in most episodes of hypertension. Side effects: Thiocyanate poisoning.
Intravenous nitro-glycerine is used in patients with acute coronary failure without contraindications, a dose of 5 - 10 mg/min.
Labetalol (Trandate), a sympathomimetic alpha and beta inhibitor, is good for acute myocardial infarction, intravenous infusion 1-2 mg/min.
Alpha Methyldopa or intravenous clonidine.
Types of ACE inhibitors: Captopril 25mg sublingual.
Often combined with intravenous Lasix.
Provision level I
For those who have not had high blood pressure, it is important to note that daily living issues, especially harmful habits of health, must be periodically examined to detect hypertension or related diseases. In this audience, attention should be paid to those with high-risk factors for disease, even though hypertension is not detected at first, but need to exchange propaganda for preventive coordination with frontline health workers.
Contingency level II
People already with hypertension, need a more strict diet, rest, regular blood pressure monitoring, and outpatient treatment plan to monitor progress and side effects of the drug. Pay attention to the economic factors of treatment because this is a long-term, expensive course.
The patient's prognosis usually depends on:
Blood pressure readings: The higher the blood pressure reading, the greater the mortality rate.
Complications: Being a prognostic factor is very important when there are complications.
Long-term prognosis: Blood cholesterol has an important position because it is easy to lead to coronary atherosclerosis, myocardial infarction in the future.
Treatment also plays a significant role, with a positive prognosis if treated early, properly, with long-term follow-up.