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) - echocardiograms will be used in order to measure electrical activity of the heart and 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 blood that your heart pumps - the amount of resistance to blood flow in your arteries. - 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. juxtaglomerular apparatuskidneysenzymereninjuxtaglomerular apparatuskidneysenzymerenin  Renin cleaves an inactive peptide called angiotensinogen, converting it into angiotensin I. peptide angiotensinogenangiotensin Ipeptide angiotensinogenangiotensin I  Angiotensin I is then converted to angiotensin II by angiotensin-converting enzyme (ACE). angiotensin II angiotensin-converting enzymeangiotensin II angiotensin-converting enzyme  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. 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

Malignant essential hypertension Benign essential hypertension  Hyalnosis  Fibrinoid Necrosis of blood vessel media  Hyalinosis  Elastosis 1- Vascular lesions Sub-capsular and interstitial hemorrhage Primary contracted small kidney 2-Renal lesions Slight hypertrophy of the left ventricle Hypertrophy of the left ventricle 3- Cardiac lesions

 Retinal exudate  Retinal hemorrhage  Retinal exudate  Retinal hemorrhage 4-Retinal lesions Massive cerebral hemorrhage  Microaneurysm  Cerebral hemorrhage 5-Cerebral lesions  Renal failure (95%)  Cerebral hge  Left sided HF  Left sided HF (60%)  Cerbrel hge (30%)  Renal failure (10%) 6-Cause of death

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 life- threatening.