5 Essential Hypertension

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Internal Medicine Page 1

Essential Hypertension

Hypertension is the persistent elevation of blood pressure as a figure

( 140/90 mmHg). The persistency has its own characteristics and so does the

elevation.

If a referred patient is complaining of high BP, his/her blood pressure should be

measured in order to confirm the diagnosis, making sure that this elevation is

persistent.

On the first visit, the blood pressure should be measured three times separated by

an interval of 5 minutes of rest, both the diastolic and the systolic BP are recorded.

The average of the three diastolic BP readings is calculated and so for the readingsof the systolic BP. They are then registered in the patients file as two measures in

one figure; one for the diastolic and the other for systolic.

The patient is asked to schedule an appointment after 2-3 weeks. He/she is advised

not to come in a hurry, after eating a large meal, drinking coffee, nor having smoked

cigarettes. These four warnings should be avoided for at least half an hour prior to

the appointment, as they will affect the blood pressure giving false readings. On this

second visit the same procedures done previously are repeated; blood pressure is

recorded three times then their average is calculated and registered.

After the two visits, if the systolic BP is 140mmHg or above, and/or the diastolic BP

is 90mmHg or above, the patient is labeled as hypertensive. A persistent elevation in

one of the two readings (systolic or diastolic) is sufficient to reach the diagnosis of

hypertension, however most hypertensive patients will probably have an elevation

in both readings.

Two variants of Hypertension that are present in a small incidence in the population

are:

1) Isolated Systolic Hypertension. 2) Isolated Diastolic Hypertension.


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Isolated Systolic Hypertension is more common in the elderly population (above 69

years of age). A patient with Isolated Systolic Hypertension will have a systolic BP of

140mmHg or above but a diastolic BP below 90mmHg.

Isolated Diastolic Hypertension is more common in young healthy patients with

Essential Hypertension. A patient with Isolated Diastolic Hypertension will have adiastolic BP of 90mmHg or above but a systolic BP below 140mmHg. It is mostly

related to the Hyperdynamic Circulation (abnormally increased circulatory volume

due to systemic vasodilation) in those patients.

As mentioned earlier, Hypertension is defined within two elements; elevation and

persistency. Elevation of BP as a figure (systolic 140mmHg, diastolic 90mmHg),

and this should be confirmed by three measurements in two separate visits, and this

elevation should be persistent. A patient that presents those two elements is

described as hypertensive.

The current classification of Hypertension is the Joint National Committee

classification (JNC) 7th report:

Normal Blood Pressure: Systolic 120mmHg and Diastolic 80mmHg. Prehypertension: Systolic between120 -139mmHg and Diastolic between 80-

89mmHg.

Stage -1 Hypertension: Systolic 140-159mmHg and Diastolic 90- 99mmHg. Stage -2 Hypertension: Systolic 160mmHg and Diastolic 100mmHg.

*Note: The table in slide 4 describes the classifications of BP and the

Pharmaceuticals used in its treatment, it is not important to memorize.

Causes of Hypertension:

Essential Hypertension (Primary Hypertension): It accounts for 95% of allcases of Hypertension, where no cause of the disease is found (Idiopathic), it

might be because of familial aggregation, as Hypertension runs in families.


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Secondary Hypertension: Accounts for about 5% of all cases, where there isan underlying cause of the disease. The following causes are ordered

according to their descending frequency where renal diseases being the most

common factor followed by drugs, endocrine diseases, then cardiovascular

diseases.

1.Renal Diseases: They are the most common factor leading to Hypertension. Theyare divided into

a) Renovascular causes:-Generalized atherosclerosis (more common): Seen in elderly patients. All

vessels in the body are susceptible to atherosclerosis; Carotid, Cerebral,

Aorta, Coronary and Renal arteries. When Renal arteries (branching from the

abdominal aorta) are affected by an atherosclerotic plaque at the

ostium(origin), a narrowing of the artery will occur there. The patient here

needs constructive surgery.

-Fibromuscular dysplasia: Congenital, seen in young adult females. Causessuccessive constriction and dilatation of the main renal arteries. This will

appear as beadings or balloon dilatations on the renal angiogram.

*Note: The doctor mentioned a few points about a procedure called BTCA

or PTCA, which were unclear, and were not mentioned in the slides.

b)Renoparenchymal causes:-Pyelonephritis inflammation of the pelvis or ureters (urinary tracts) of

the kidney-Chronic glomerulonephritis: Inflammation of the kidney. Note that acute

glomerulonephritis does not cause Hypertension.

-Obstructive uropathy: Obstruction of urine flow.-Polycystic kidney disease.-Hypernephromas: Tumors of the kidney


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2.Drugs: The most common drugs that are associated with Hypertension areSteroids, Contraceptive pills, NSAIDS, Carbenoxolone and Liquorice (outdated

drugs, were used to treat peptic ulcer by coating the mucosal layer, now they are

replaced by PPIs), sympathomimetics (nasal drops used by elderly to clear nasal

stiffness).

3.Endocrine Diseases:- Hyperparathyroidism- Pheochromocytoma- Hypothyroidism- Cushings Syndrome (high levels of Cortisol)- Acromegaly (high levels of growth hormone)- 1 Aldosteronism (high levels of Aldosterone)

The only Endocrine diseases not associated with hypertension:

- Addisons Disease (low levels of steroids)- Hypoparathyroidism

4.Cardiovascular Disease: The only cardiovascular disease that causesHypertension is Coarctation of the Aorta.

5.Other Causes:- Brain tumors: Not all brain tumors cause Hypertension, only those that

cause increased intracranial pressure.

- Bulbar poliomyelitis (form of infection by Poliovirus)- Lead poisoning- Cocaine abuse- Connective tissue disorders i.e SLE and Polyarteritis Nodosa- Diabetes Mellitus Nephropathy- Polycythemia Rubra Vera


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Initial and Primary Investigations in Hypertension:

The following investigations are a must for every hypertensive patient once the

diagnosis is established, to know if there is an underlying cause behind the disease.

Urinalysis (to check for hematuria or proteinuria) Renal profile ECG Chest x-ray Plain U-T x-ray, Plain KUB x-ray ( Kidney, Ureter, Bladder), or renal

ultrasound (to assess kidney size and presence of renal stones or associated

uropathy)

Urine culture: For patients with possible Acute Ascending Pyelonephritis orReflux Uropathy. This is specially seen in female adult teenagers (12yo-15yo),

where it will be the most probable cause of Hypertension in those females. It

has a specific investigation called Voiding Urethrogram.

HB, PCV FBS, S.lipids ,S.urate Echocardiography

When to investigate for a secondary cause of hypertension

Sophisticated investigations are costly (expensive), invasive(dangerous) in nature

and chances of finding an underlying cause is 5%. They are not done unless we

have:

1. Clues from the history: for example a patient with a history of triad ofpalpitations, headache, excessive sweating and a rise in blood pressure,

Pheochromocytoma (a tumor of the supra renal gland) might probably be the

cause. Investigations may include renal CT scan, selective renal arteriogram

or biochemical work up to diagnose this condition.


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2. Clues from physical examination:- if masses were detected on one lobe, one might think of Polycystic

Kidney Disease.

- If striae (stretch marks) on the abdomen and mooning of the face, itmight be due to Cushings syndrome, and so further investigations are

needed to confirm that.

3. Clues from initial investigations:- If the lab works up showed persistent hypokalemia, it might be due to

Primary Hyperaldosteronism (Conns Syndrome).

- If urine tests indicate hematuria or proteinuria. It might beGlomerulonephritis, which might require a biopsy depending on the

kidney size.

4. Malignant stage hypertensionEx. Renal biopsies, Renal angiogram etc. as they may cause bleeding

due to dissection, kidney perforation etc.

Complications of hypertension:

Hypertension is a silent killer, meaning that it is largely an asymptomatic disease.

Patients dont usually complain of specific symptoms associated with the disease.

For instance, headaches are thought to be closely related to hypertension, but in fact

theyre not. They are justa common disease in the community so is Hypertension,

and the presence of these two common diseases in the same patient is a common

finding. Against traditional believes, hypertension doesnt cause headaches unless it

is in the malignant stage or it has caused cerebral bleeding. So, these two diseasesare not correlated.


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However, Hypertension may be associated with epistaxis, general fatigue or

weakness. These symptoms are not that specific for Hypertension as the might be

linked to various systemic diseases.

Complications of Hypertension are usual; they are summed up in the followingpoints:

Cardiovascular: Angina, Myocardial Infarction, Left Ventricular Hypertrophy,Heart failure, dissecting aortic aneurysm, Cardiomegaly.

Cerebrovascular: Transient Ischemic Attack, Thrombotic Cerebral Infarction,Intracerebral Hemorrhage, Hypertensive Encephalopathy

Peripheral vascular disease (atherosclerosis, Intermittent claudication,gangrene)

Retinopathy (Grades 1,2,3,4) Nephropathy: Raise in Creatinine level, Hypokalemia, Nephrosclerosis,

Fibrinoid Necrosis.

Malignant Hypertension: Severe stage Hypertension with Systolic 180mmHg and Diastolic 110mmHg, and grade 3 or 4 Retinopathy

(Grade 3: soft exudate and hemorrhage, Grade 4: papilledema + soft exudate

and hemorrhage). If not treated, it may lead to renal failure, heart failure,

blindness, and other complications.

Treatment of Hypertension:

Non-pharmacological measures:

1. Diet

2. Weight reduction

3. Stopping smoking and excess alcohol consumption4. Regular exercise ( behavioral, biofeedback therapy)

5. Treatment of other associated risk factors


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Nowadays, there is six groups of antihypertensive drugs divided into different

classes. A physician should be familiar with at least one drug from each class, and

familiar here implies that this physician should have complete knowledge of this

drug in terms of dosage, frequency of administration, side effects, precautions, and

complications

Antihypertensive medications:

*Note: only memorize drug classes.

1. Diuretics-Thiazide: very weak diuretic effect, it stimulates vasodilation in the arterialwalls by relaxing the smooth muscles of these vessels.

--Loop: they are not used as an antihypertensive drug unless the condition wasassociated with fluid retention due to heart failure and renal failure.

-K+ sparing2. Beta-Blockers: Widely used drugs, used to treat hypertension as well as many

other conditions like heart failure, migraine prophylaxis, tachycardial essential

tremor, angina etc

Ex:- Non-Cardioselective, Cardioselective, Drugs with ISA, Alpha and Beta-

blockers (labetolol).

3.Alpha-blockers ( prazosin)4. Central acting drugs: Not used as much nowadays. Ex: Reserpine, Methyldopa,

and Clonidine.


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5.Vasodilators:

a) Direct relaxation of arteriolar smooth muscle: Specially peripheralvasodilators. A common side effect is Orthostatic Hypotension, which causes

distress. Have been replaced by other classes.Ex: -Hydralazin -Minoxidil Diazoxide -Na Nitroprusside

b) Calcium-channel blockers: - Verapamil - Nifedipine - Amlodipine

c) ACE inhibitors: Angiotensin Converting Enzymes Inhibitors

Ex: - Captopril - Enalapril - Lysinopril - Quinapril

6. ARBs: Angiotensin Renin Blockers

Ex: - Losartan - Candesartan - Irbisartan - Valsartan

Hypertensive Crisis (Hypertensive Emergency):

Severe hypertension (>180/110mmHg) with one of the following:

1. Heart failure2. MI3. Renal failure4. Encephalopathy5. Dissecting aneurysm6. Intracerebral hemorrhage7. Accelerated or malignant hypertension

Hypertensive crisis requires rapid action and treatment with parenteral

medications (Direct IV infusion, direct IV boluses or subcutaneous infusions) to

reduce blood pressure in a matter of minutes rather than hours or days.

NOTE: Blood pressure shouldnt be reduced to below diastolic of 100 mmHgParenteral Drugs Used In Hypertensive Emergencies are not to memorize.

Done by: Raya Dawood & Lama Ashour

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5 Essential Hypertension