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Hypertension
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فهرست
فشارخون
تعریف افزایش فشارخون
افزایش فشارخون اولیه
افزایش فشارخون ثانویه
تظاهرات بالینی
مدیریت پزشکی
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Blood pressure
Blood pressure is the product of cardiac output and peripheral resistance.
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Blood pressure
High blood pressure, known as hypertension, can result from a change in cardiac output, a change in peripheral resistance, or both.
The medications used for treating hypertension decrease peripheral resistance, blood volume, or the strength and rate of myocardial contraction.
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Hypertension Defined
Hypertension is a systolic blood pressure greater than 140 mm Hg and a diastolic pressure greater than 90 mm Hg over a sustained period, based on the average of two or more blood pressure measurements taken in two or more contacts with the health care provider after an initial screening
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Hypertension Defined
The classification shows the direct relation between the risk of morbidity and mortality from hypertension and the level of systolic and diastolic blood pressures.
The higher the systolic or diastolic pressure, the greater the risk
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Hypertension Defined
Even within the normotensive range, three levels of blood pressure— optimal, normal, and high-normal—were specified to emphasize that the lower the blood pressure, the lower the risk.
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Hypertension Defined
The JNC VI also developed recommendations for follow-up monitoring according to initial blood pressure readings at the time of diagnosis
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JNC VI: Sixth Joint National Committee
JNC VI: Sixth Joint National Committee on the Prevention, Detection, Evaluation and Treatment of High Blood Pressure;
committee established to study and make recommendations about hypertension in the United States.
Findings and recommendations of JNC VI are contained in an extensive report published in 1997
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Primary Hypertension
Between 20% and 25% of the adult population in the United States has hypertension
Of this population, between 90% and 95% have primary hypertension, meaning that the reason for the elevation in blood pressure cannot be identified.
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Secondary hypertension
The remaining 5% to 10% of this group have high blood pressure related to specific causes, such as narrowing of the renal arteries, renal parenchymal disease, hyperaldosteronism (mineralocorticoid hypertension) certain medications, pregnancy
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Secondary hypertension
Secondary hypertension is the term used to signify high blood pressure from an identified cause.
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Hypertension
Hypertension is sometimes called “the silent killer” because people who have it are often symptom free.
In a national survey (1991 to 1994), 32% of people who had pressures exceeding 140/90 mm Hg were unaware of their elevated blood pressure
Once identified, elevated blood pressure should be monitored at regular intervals because hypertension is a lifelong condition.
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Hypertension
Cigarette smoking does not cause high blood pressure;
however, if a person with hypertension smokes, his or her risk of dying from heart disease or related disorders increases significantly.
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Hypertension
Prolonged blood pressure elevation eventually damages blood vessels throughout the body, particularly in target organs such as the heart, kidneys, brain, and eyes.
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Hypertension
The usual consequences of prolonged, uncontrolled hypertension are
myocardial infarction
heart failure
renal failure
strokes
impaired vision.
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Hypertension
The left ventricle of the heart may become enlarged (left ventricular hypertrophy) as it works to pump blood against the elevated pressure.
An echocardiogram is the recommended method of determining whether hypertrophy (enlargement) has occurred
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Clinical Manifestations
Physical examination may reveal no abnormalities other than high blood pressure.
Occasionally, retinal changes such as hemorrhages, exudates (fluid accumulation), arteriolar narrowing occur
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Clinical Manifestations
In severe hypertension, papilledema (swelling of the optic disc) may be seen.
People with hypertension can be asymptomatic and remain so for many years.
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Clinical Manifestations
Coronary artery disease with angina or myocardial infarction is a common consequence of hypertension.
Left ventricular hypertrophy occurs in response to the increased workload placed on the ventricle as it contracts against higher systemic pressure.
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Clinical Manifestations
When heart damage is extensive, heart failure ensues.
Pathologic changes in the kidneys (indicated by increased blood urea nitrogen [BUN] and creatinine levels) may manifest as nocturia
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Clinical Manifestations
Cerebrovascular involvement may lead to a stroke or transient ischemic attack (TIA),
manifested by alterations in vision or speech, dizziness, weakness, a sudden fall, or temporary paralysis on one side (hemiplegia).
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Medical Management
The goal of hypertension treatment is to prevent death and complications by achieving and maintaining the arterial blood pressure at 140/90 mm Hg or lower.
The JNC VI specified a lower goal pressure of 130/85 mm Hg for people with diabetes mellitus or with proteinuria greater than 1 g per 24 hours
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