Download 2- Secondary hypertension

Hypertension
DR. Gehan Mohamed
Arteriolosclerosis
(Hypertension)
 When we diagnose hypertension?
– When there is Persistent elevation of the blood pressure
above 140/90 mmHg.
– N.B it is called malignant hypertension if Systolic blood
pressure >220 and diastolic >120mmHg with acute
impairment of an organ system (e.g., central nervous system
[CNS], cardiovascular, renal).
What are symptoms of hypertension?
 1- About 33% of people are asymptomatic. For
this reason, it is advisable to undergo periodic
blood pressure screenings.
 2- symptomatic specially in Extremely high
blood pressure may lead to : - headaches , - Fatigue ,Dizziness ,confusion
- ,Nausea ,- Problems with vision
- Chest pains ,-Breathing problems ,- Irregular
heartbeat
- Blood in the urine
investigations
 Hypertension can be measured by a device
called a sphygmomanometer - the device
with the arm cuff.
 tests such as:
- electrocardiograms (ECG) used in order to
measure electrical activity of the heart .
-echocardiograms will be used to assess the
physical structure of the heart.
pathophysiology
 With every heart beat, the heart pumps blood
through the arteries to the rest of the body.
 Blood pressure is the force of blood that is
pushing up against the walls of the blood
vessels.
 If the resistance exerted by the blood vessels
is too high, the heart has to work harder to
pump, and this could lead to organ damage.
What are the factors which
determine hypertension
 Blood Presure =
Cardiac Output x Prepheral Resistance
 So Blood pressure is determined by :
- the amount of blood that your heart pumps
- the amount of resistance to blood flow in your
arteries.
The more blood your heart pumps and the
narrower your arteries, the higher your blood
pressure.
Mechanism of hypertension
ReninAngiotensinAldosterone

If the perfusion of the juxtaglomerular apparatus in
the kidneys decreases, then the juxtaglomerular
cells release the enzyme renin.
 Renin cleaves an inactive peptide called
angiotensinogen, converting it into angiotensin I.
 Angiotensin I is then converted to angiotensin II by
angiotensin-converting enzyme (ACE).
 Angiotensin II is the major bioactive product of the
renin-angiotensin system.
 Angiotensin II causes :
A- vasoconstriction of the blood vessels
B- increase aldosterone secretion causing fluid
retention
risk factors for hypertension
 1- Age & sex : The risk of hypertension
increases as you age due to atherosclerosis,
 also more common in men. Women are more
likely to develop high blood pressure after
menopause.
 2- Race. Hypertension more among blacks.
 3- Certain chronic conditions as high
cholesterol, diabetes, kidney disease
 4- Sometimes pregnancy contributes to high
blood pressure.
risk factors for hypertension
 5-Family history. High blood pressure
tends to run in families.
 6- Being overweight or obese. The more
you weigh, the more blood you need to
supply oxygen and nutrients to your tissues.
As the volume of blood circulated through
your blood vessels increases, so does the
pressure on your artery walls.
risk factors for hypertension
 7- physically inactive tend to have higher
heart rates. The higher your heart rate, the
harder your heart must work with each
contraction — and the stronger the force on
your arteries.
Lack of physical activity also increases the
risk of being overweight.
risk factors for hypertension
 8-Using tobacco. the chemicals in tobacco
can damage the lining of your artery walls.
This can cause your arteries to narrow,
increasing your blood pressure.
 9-Too much salt (sodium) in your diet can
cause your body to retain fluid, which
increases blood pressure.
risk factors for hypertension
 10-Too little potassium in your diet. If you
don't get enough potassium in your diet or
retain enough potassium, you may
accumulate too much sodium in your blood.
risk factors for hypertension
 11-Drinking too much alcohol. Over time, can
damage your heart. can also temporarily raise
your blood pressure, as it may cause your body
to release hormones that increase your blood
flow and heart rate.
 12- Stress. High levels of stress can lead to a
temporary increase in blood pressure.
Types of hypertension
Hypertension is divided according to presence of known
etiology or no into two categories:
1- Primary (essential) hypertension (95%) : OF UNKNOWN
cause ,tends to develop gradually over many years.
2- Secondary hypertension (5%) : secondary to another
diseases
this type of hypertension tends to appear suddenly and cause
higher blood pressure than does primary hypertension.
– Both primary or secondary hypertension can be Benign
Or Malignant according to the degree in rise of BP so
If BP exceed 220/120 it is called malignant hypertension.
Causes of Secondary
hypertension
 Renal diseases causes release of renin
–
–
–
–
–
Acute and chronic glomerulonephritis
Chronic pyelonephritis
Hydronephrosis
Polycystic kidney
Renal artery stenosis
 Endocrine diseases
– Pheochromocytoma(tumor arise from adrenal medulla
which secret excess epinephrine which is
vasoconstrictor)
– Cushing syndromes (in it increase secretion of
glucocorticoids)
 Cardiovascular diseases
– Co-arctation of aorta : i.e congenital narrowing of aorta
which resist entrance of blood inside it .
high blood pressure in children
 For some children, high blood pressure is
caused by problems with :
-the kidneys or heart (secondary
hypertension).
- poor lifestyle habits such as an unhealthy
diet and lack of exercise contribute to high
blood pressure.
Differences between benign and
malignant hypertension
Benign essential
hypertension
1Hyalinosis
Vascular Elastosis
lesions
Malignant essential
hypertension
Hyalnosis
Fibrinoid Necrosis of
blood vessel media
2-Renal
lesions
Primary contracted Sub-capsular and
small kidney
interstitial
hemorrhage
3Cardiac
lesions
Hypertrophy of the Slight hypertrophy of
left ventricle
the left ventricle
4-Retinal lesions Retinal exudate Retinal exudate
Retinal
Retinal
hemorrhage
hemorrhage
5-Cerebral
lesions
Microaneurysm Massive
cerebral
Cerebral
hemorrhage
hemorrhage
6-Cause of
death
Left sided HF
(60%)
Cerbrel hge
(30%)
Renal failure
(10%)
Renal failure
(95%)
Cerebral hge
Left sided HF
HISTOPATHOLOGY of ESSENTIAL HYPERTENSION: showing
thickening of arterial wall due to hyaline change of collagen fibers
Complications of hypertension
 1-The higher your blood pressure and the
longer it goes uncontrolled, the greater the
damage to the wall of the blood vessels.
 2- Weakened and narrowed blood
vessels in your kidneys. This can prevent
these organs from functioning normally.
 3-Thickened, narrowed or torn blood
vessels in the eyes. This can result in
vision loss.
Complications of hypertension (cont.)
 4- Heart attack or stroke. High blood
pressure can cause atherosclerosis, which can
lead to a heart attack, stroke.
 5- Heart failure. To pump blood against the
higher pressure in your vessels, your heart
muscle thickens. Eventually, the thickened
muscle may have a hard time pumping enough
blood to meet your body's needs, which can
lead to heart failure.
Complications of hypertension
(cont.)
 6- Aneurysm: Increased blood pressure
can cause your blood vessels to weaken
and bulge, forming an aneurysm. If an
aneurysm ruptures, it can be lifethreatening.