Investigations of Hypertension

INVESTIGATIONS OF HYPERTENSION / HIGH BLOOD PRESSURE

Blood pressure is the product of Cardiac out put & peripheral vascular

resistance. change in either one of them or both results in change in

blood pressure.During daily life activity blood pressure varies, because

of constant change in the cardiac output & peripherial resistance.

Blood pressure could rise during mental stress or anxiety but these

transient elevations of blood pressure are not considered diagnostic.

A constant rise of blood pressure throughout the day is a diagnostic

feature of hypertension (high blood pressure).

After the diagnosis, the following information is necessary for the

investigations of high blood pressure / Hypertension.

1) Family History of high blood pressure.2) physical Examination.

3) Laboratory investigations. 4) Radiological Examination

5) ECG 6) Special investigations.

When investigating these patients, it is important to assess.

a) The degree of hypertension (mild, moderate or severe).

b) Involment of target organs like heart, brain, kidneys, eyes and

peripheral arteries.

c) Evidence of target organ damage such as ischaemic heart disease,

heart failure, stroke, kidney failure and eye changes.

d) Is this increase in blood pressure Curable?

Systemic symptoms in Hypertension
------------------------------------------------------
Heart .... Chest pain, Breathlessness, palpitation & swelling of the legs

Kidney...... Dysuria, Nocturia, Frequency of Micturition.

Central Nervous
system ...... Headache, Dizziness, Hemiplegia, Hemianopia.

Fundus ............ Blurring of vision.

Blood pressure
------------------------

Normal blood pressure is 120/80 but can vary from 90/70 to 140/90.

as age advances blood pressure steadily.

Note : - Blood pressure of 140/90 in a 20 years old patient is abnormal

and needs investigations.

I ) Cardiovascular Examination : - on ausculation of the heart, aortic

heart sound is loud; fourth heart sound may be heard, due to decrease

distensibility of the left ventricle from thickened left ventricular muscle.

Left ventricular hypertrophy occurs; this will be followed by left ventricular

failure. Congestion in the lungs can be detected by auscultation.. It is a

sign of left ventricular.

II ) Examination of the fundus of the eye : - On fundal examination

arteriolar narrowing, irregularity and arteriovenous nipping (for nickling)

In advanced stages of hypertension, haemorrhages and exudates are

seen in the retina. Papilloedema with blurring of the disc margins is the

end stage.

III ) Central Nervous System : - In early stages no abnormality could be

detected. When brain damage occurs from severe hypertension,

evidence of hemiplegia may be detected. On examination, plantars

may be up going with weakness of the paralysed side.

I V ) Kidneys : - Urinary symptoms may occur from renal disease.

Long standing hypertension causes shrinkage of the kidney size

and scarring of the glomeruli affecting the function.

Kidneys are enlarged and palpable in polycystic disease.

V ) Laboratory Investigations: - are done to establish the cause and

evidence of involment of the target organs from long standing

hypertension.

a ) Urine : - Urine analysis gives lot of information about the renal

pathology. Proteinuria occurs in renal disease.

Specific gravity around 1010 ( fixed specific gravity) suggest chronic

renel failure. Granular casts & pus cells appear in the urine.

Bacterial culture examination done. Positive culture is found in

urinary tract infection. or chronic pyelonephritis..

b ) Blood tests : - In kidney disease, blood urea nitrogen and

serum creatinine are elevated.

c) Serum potassium level is low in primary aldosteronism.

In patients with long standing blood pressure with kidney

damage, serum level is high.

VI ) Radiological Examination : - a) Chest X- ray:

sometimes heart size may be normal ,

as the muscle mass of the left ventricle may have increased

Concentrically. Usually left ventricular enlargement is seen on the

border of the heart.

b) Intravenous pyelogram : - This test may give evidence of renal

parenchymal disorder or renal artery stenosis as a cause of

hypertension.

V I I ) ECG : - most useful investigation in confirming the left ventricular

hypertrophy. I t is a reliable investigation even though chest x - ray

may not show any evidence of the left ventricular enlargement.

ECG shows evidence of hypertrophy and not dilatation.

TESTS AND THEIR PURPOSE
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TEST PURPOSE OF INVESTIGATION

URINE -------------> Evidence of kidney disease.

BUN

a) Serium Creatinine ------> To assess kidney function.

b) potassium -------> Low in primary hyperaldosteronism

High in Chronic renal failure.

HAEMOGLOBIN --------> Low in chronic renal disease.

CHEST X - RAY ---------->Evidence of left ventricular Enlargement

or / and failure.

ECG ---> To assess left ventricular hypertrophy.

I. V. P ---> To assess renal pathology and function.

Writer......... Dr HC Sathya MRCP.

Summary by R.Krishnakumar.