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INTRODUCTION

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  • Hypertension is defined as persistently elevated arterial blood pressure (BP). The classification of BP in adults (age 18 years and older) is shown in Table 10–1.

  • Isolated systolic hypertension is diastolic blood pressure (DBP) values less than 90 mm Hg and systolic blood pressure (SBP) values of 140 mm Hg or more.

  • Hypertensive crisis (BP >180/120 mm Hg) may be categorized as hypertensive emergency (extreme BP elevation with acute or progressing end-organ damage) or hypertensive urgency (high BP elevation without acute or progressing end-organ injury).

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Table Graphic Jump Location
TABLE 10–1Classification of Blood Pressure in Adults
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PATHOPHYSIOLOGY

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  • Hypertension may result from an unknown etiology (primary or essential hypertension) or from a specific cause (secondary hypertension). Secondary hypertension (<10% of cases) is usually caused by chronic kidney disease (CKD) or renovascular disease. Other conditions are Cushing syndrome, coarctation of the aorta, obstructive sleep apnea, hyperparathyroidism, pheochromocytoma, primary aldosteronism, and hyperthyroidism. Some drugs that may increase BP include corticosteroids, estrogens, nonsteroidal anti-inflammatory drugs (NSAIDs), amphetamines, sibutramine, cyclosporine, tacrolimus, erythropoietin, and venlafaxine.

  • Factors contributing to development of primary hypertension include:

    • ✓ Humoral abnormalities involving the renin–angiotensin–aldosterone system (RAAS) or natriuretic hormone;

    • ✓ Disturbance in the CNS, autonomic nerve fibers, adrenergic receptors, or baroreceptors;

    • ✓ Abnormalities in renal or tissue autoregulatory processes for sodium excretion, plasma volume, and arteriolar constriction;

    • ✓ Deficiency in synthesis of vasodilating substances in vascular endothelium (prostacyclin, bradykinin, and nitric oxide) or excess vasoconstricting substances (angiotensin II, endothelin I); and

    • ✓ High sodium intake or lack of dietary calcium.

  • Main causes of death are cerebrovascular events, cardiovascular (CV) events, and renal failure. Probability of premature death correlates with the severity of BP elevation.

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CLINICAL PRESENTATION

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  • Patients with uncomplicated primary hypertension are usually asymptomatic initially.

  • Patients with secondary hypertension may have symptoms of the underlying disorder. Patients with pheochromocytoma may have headaches, sweating, tachycardia, palpitations, and orthostatic hypotension. In primary aldosteronism, hypokalemic symptoms of muscle cramps and weakness may be present. Patients with Cushing syndrome may have weight gain, polyuria, edema, menstrual irregularities, recurrent acne, or muscular weakness in addition to classic features (moon face, buffalo hump, and hirsutism).

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DIAGNOSIS

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  • Elevated BP may be the only sign of primary hypertension on physical examination. Diagnosis should be based on the average of two or more readings taken at each of two or more clinical encounters.

  • Signs of end-organ damage occur primarily in the eye, brain, heart, kidneys, and peripheral blood vessels.

  • Funduscopic examination may reveal arteriolar narrowing, focal arteriolar constrictions, arteriovenous nicking, retinal hemorrhages and exudates, and disk edema. Presence of papilledema usually indicates a hypertensive emergency requiring rapid treatment.

  • Cardiopulmonary examination may reveal abnormal heart rate or rhythm, left ventricular (LV) hypertrophy, coronary heart disease, or heart failure (HF).

  • Peripheral vascular examination may reveal aortic or abdominal bruits, distended veins, diminished or absent peripheral pulses, or lower extremity edema.

  • Patients with renal artery stenosis may have an ...

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