Hypertension PDF 2020

1 2 What is arterial blood pressure? Blood pressure (BP) is the pressure exerted by circulating blood upon the walls of blood vessels and is one of the principal vital signs. 3  Blood pressure is expressed by two measuremen...

1 2 What is arterial blood pressure? Blood pressure (BP) is the pressure exerted by circulating blood upon the walls of blood vessels and is one of the principal vital signs. 3  Blood pressure is expressed by two measurements, the systolic and diastolic pressures, which are the maximum and minimum pressures, respectively. 4 5 6 Blood pressure is recorded as two numbers: the systolic and diastolic pressures. Systolic blood pressure is the maximum pressure during a heartbeat. Diastolic blood pressure is the lowest pressure between heartbeats. Blood pressure is measured in millimeters of mercury (mm Hg) and is written systolic over diastolic (for example, 120/80 mm Hg, or "120 over 80"). 7 What is the medical diagnosis for hypertension? One high reading does not mean you have high blood pressure. It is necessary to measure the blood pressure at different times, while you are resting comfortably for at least five minutes. To make the diagnosis of hypertension, at least three readings that are elevated are usually required. 8  Definition of hypertension Hypertension is defined as persistent elevation of arterial blood pressure. The diagnosis of hypertension is made when diastolic blood pressure is higher than 90 mmHg and the systolic blood pressure is higher than 140 mmHg. The measurement of blood pressure should be done at least three on at least three subsequent visits. 9  Blood pressure measurements fall into four general categories: Normal blood pressure. The blood pressure is normal if it's below 120/80 mm Hg. Prehypertension. Prehypertension is a systolic pressure ranging from 120 to 139 mm Hg or a diastolic pressure ranging from 80 to 89 mm Hg. Prehypertension tends to get worse over time. Hpertension is made when diastolic blood pressure is higher than 90 mmHg and the systolic blood pressure is higher than 140 mmHg. 10  Grading of Hypertension Mild hypertension (stage 1): Systolic pressure is 140-159 mmHg and diastolic pressure is 90-99 mmHg Moderate hypertension (stage 2): Systolic pressure is 160-179 mmHg and diastolic pressure is 100-109 mmHg Severe hypertension = hypertensive crisis (stage 3): Systolic pressure is >180mmHg and diastolic pressure is >110 mmHg 11 Types & classification of hypertension There are two types of hypertension: Primary (essential) hypertension Secondary hypertension 12 Primary (essential) Hypertension It accounts for more than 90-95% of cases. It is of unknown aetiology (idiopathic), there's no identifiable cause of high blood pressure. it tends to be familial and is likely to be the consequence of an interaction between environmental and genetic factors. Prevalence of essential hypertension increases with age, and individuals with relatively high blood pressure at younger ages are at increased risk for the subsequent development of hypertension. It occurs mostly in middle and old age. Factors that may play role in the aetiology include: 1- increased sympathetic activity. 2- increased renin secretion. 13 Factors that play a role in the pathogenesis of primary hypertension: 1- increased sympathetic activity: There is increased activity of sympathetic system which results in vasoconstriction and increase of peripheral vascular resistance. 2- increased renin secretion: There is increased renal secretion of renin due to unknown cause. Renin converts angiotensinogen into angiotensin I which is then converted to angiotensin II (by angiotensin converting enzyme) leading to vasoconstriction, secretion of aldosterone which leads to salt and water retention. 14 Risk factors High blood pressure has many risk factors, including: Age. The risk of hypertension increases with aging. Through early middle age, or about age 45, high blood pressure is more common in men. Women are more likely to develop high blood pressure after age 65. Race. High blood pressure is particularly common among blacks, often developing at an earlier age than it does in whites. Serious complications, such as stroke, heart attack and kidney failure, also are more common in blacks. Family history. High blood pressure tends to run in families. Being overweight or obese. The more the weight the more blood body need to supply oxygen and nutrients to the tissues. As the volume of blood circulated through theblood vessels increases, so does the pressure on the artery walls. 15 Risk factors (cont.) Not being physically active. People who are inactive tend to have higher heart rates. The higher the heart rate, the harder the heart must work with each contraction and the stronger the force on the arteries. Lack of physical activity also increases the risk of being overweight. Using tobacco. Not only does smoking or chewing tobacco immediately raise the blood pressure temporarily, but the chemicals in tobacco can damage the lining of the artery walls. This can cause the arteries to narrow, increasing the blood pressure. Secondhand smoke also can increase the blood pressure. Too much salt (sodium) in your diet. Too much sodium in the diet can cause the body to retain fluid, which increases blood pressure. Too little potassium in your diet. Potassium helps balance the amount of sodium in the cells. If body don't get enough potassium in the diet or retain enough potassium, this may accumulate too much sodium in the blood. Too little vitamin D in your diet. It's uncertain if having too little vitamin D in the diet can lead to high blood pressure. Vitamin D may affect an enzyme produced by the kidneys that affectsthe blood pressure. 16 Risk factors (cont.) Stress. High levels of stress can lead to a temporary increase in blood pressure. If you try to relax by eating more, using tobacco or drinking alcohol, you may only increase problems with high blood pressure. Certain chronic conditions. Certain chronic conditions also may increase your risk of high blood pressure, such as kidney disease, diabetes and sleep apnea. Drinking too much alcohol. Over time, heavy drinking can damage the heart. Having more than two drinks a day for men and more than one drink a day for women may affect the blood pressure. Sometimes pregnancy contributes to high blood pressure, as well. 17 Secondary Hypertension It accounts for about 5-10% of cases. It results secondarily from medical diseases or medications (i.e. the cause is known). 18 Causes of secondary hypertension (1) Renal causes: (A) Renal parenchymal diseases: Glomerulonephritis. Diabetic nephropathy. Polycystic kidney. (B) Renovascular (renal artery stenosis) disease: Atherosclerosis Vasculitis. Fibromuscular dysplasia. the muscle and fibrous tissues of the renal artery wall thicken and harden Renal artery thrombosis or embolism. 19 Causes of secondary hypertension (Cont.) (2) Endocrinal causes: Cushing syndrome. It is adrenal gland (adrenal cortex) hyperfunction disorder leading to excess release of cortisol hormone. Also, patients on corticosteroid therapy for long time may lead to Cushing syndrome. Aldosteronism. In this condition, a tumor in the adrenal gland (adrenal cortex), or adrenal gland hyperplasia may cause the adrenal glands to release an excessive amount of the hormone aldosterone. This makes the kidneys retain salt and water and lose too much potassium, which raises blood pressure. Pheochromocytoma. This rare tumor, usually found in an adrenal gland (adrenal medulla), increases production of the hormones adrenaline and noradrenaline, which can lead to long-term high blood pressure or short-term spikes in blood pressure. Thyroid problems. When the thyroid gland doesn't produce enough thyroid hormone (hypothyroidism) or produces too much thyroid hormone (hyperthyroidism), high blood pressure can result. Hyperparathyroidism. The parathyroid glands regulate levels of calcium and phosphorus in the body. If the glands secrete too much parathyroid hormone, the amount of calcium in the blood rises — which triggers a rise in blood pressure. 20 Causes of secondary hypertension (Cont.) (3) Miscellaneous causes: Coarctation of the aorta. is a congenital disorder, in which a part of the aorta is narrower than usual. This forces the heart to pump harder to get blood through the aorta and to the rest of the body. This, in turn, raises blood pressure — particularly in the arms. Sleep apnea. In this condition, often marked by severe snoring, breathing repeatedly stops and starts during sleep, causing patient to not get enough oxygen. - Not getting enough oxygen may damage the lining of the blood vessel walls, which may make the blood vessels less effective in regulating the blood pressure. In addition, sleep apnea causes part of the nervous system to be overactive and release certain chemicals that increase blood pressure. Pregnancy : pregnancy-induced hypertension or pre-eclampsia. 21 Causes of secondary hypertension (Cont.) (4) Medications and supplements. Various prescription medications — such as non-steroid anti- inflammatory drugs (NSADs), steroids, birth control pills (contraceptive pills), antidepressants and drugs used after organ transplants — can cause or aggravate high blood pressure in some people. Over-the-counter decongestants and certain herbal supplements, including ginseng, licorice and ephedra (ma huang), may have the same effect. Many illegal drugs, such as cocaine and methamphetamine, also increase blood pressure. 22 Symptoms Asymptomatic: Hypertension is called a "silent killer". Most people with hypertension are unaware of the problem because it may have no warning signs or symptoms. For this reason, it is essential that blood pressure is measured regularly. Headache, tinnitus, dizziness, epistaxis & palpitation. Symptoms of complications. Symptoms of the cause in secondary hypertension. 23  Complications (1) Cardiovascular complications: 1- hypertension is an important risk factor for atherosclerosis which may lead to: Coronary heart disease. Cerebral strokes Peripheral vascular disease. 2- diastolic dysfunction of the left ventricle. 3- Pressure overload on the left ventricle leading to hypertrophy and latter on heart failure. 4- Aortic dissection. 24  Complications (2) Cerebrovascular complications Cerebral atherosclerosis and thrombosis Intracranial hemorrhage Hypertensive encephalopathy (3) Renal complications e.g.Renal failure (4) Retinal complications: retinal ischemia and retinal infarction. (5) Blood vessels: wide spread atheroma formation especially if other risk factors are present e.g. dyslipidemia, smoking, diabetes..etc 25 26 Hypertensive crisis Severely elevated blood pressure (equal to or greater than a systolic 180 or diastolic of 110) is referred to as a hypertensive crisis. Hypertensive crisis is categorized as either: hypertensive urgency or hypertensive emergency, according to the absence or presence of end organ damage, respectively. 27  In hypertensive urgency, there is no evidence of end organ damage resulting from the elevated blood pressure. In these cases, oral medications are used to lower the BP gradually over 24 to 48 hours. 28  In hypertensive emergency, there is evidence of direct damage to one or more organs. The most affected organs include the brain, kidney, heart and lungs, producing symptoms which may include confusion, drowsiness, chest pain and breathlessness. In hypertensive emergency, the blood pressure must be reduced more rapidly to stop ongoing organ damage. 29 Hypertensive emergency Malignant hypertension is marked hypertension with retinal hemorrhages, exudates, or papilledema. There may also be renal involvement, called malignant nephrosclerosis. Hypertensive encephalopathy refers to the presence of signs of cerebral edema caused by breakthrough hyperperfusion from severe and sudden rises in blood pressure. 30  Treatment Life style modification: cessation of smoking, weight loss, alcohol cessation. Low salt diet and exercise. Antihypertensive medications: diuretics, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, alpha adrenergeic blockers, direct vasodilators, B blockers and centrally acting antihypertensives. 31