Hypertension, Systemic

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Elevated blood pressure: 120–129/< 80 mm Hg

• Hypertension stage 1: 130–139/80–89 mm Hg

• Hypertension stage 2: ≥ 140/≤ 90 mm Hg

GENERAL CONSIDERATIONS

• Hypertension prevalence is about one-third of the adult population of the United States and rises with age such that the majority of older Americans have hypertension

• The mechanisms of hypertension are complex, but systemic vascular resistance and stroke volume are major determinants of blood pressure

• Diastolic blood pressure is a major determinant of cardiovascular disease in younger patients, but systolic blood pressure and the pulse pressure (difference between systolic and diastolic pressure) are more important in older individuals

• Overactivity of the sympathetic nervous system can cause hypertension by increasing stroke volume and peripheral resistance

• Increases in the hormones in the renin-angiotensin-aldosterone system (RAAS) also cause hypertension by inducing salt and water retention and vasoconstriction

• Systemic hypertension is associated with insulin resistance, glucose intolerance, hyperlipidemia, and truncal obesity

• Systemic hypertension often leads to left ventricular hypertrophy, altered diastolic filling, and eventually heart failure

• The major complications are stroke, myocardial infarction, and heart and renal failure

• Treatment of even moderate hypertension lowers the risk of these complications

• African-Americans have a greater prevalence of hypertension than do whites, and they have a higher incidence of severe hypertension

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Most are asymptomatic

• Headache, nosebleeds, and other symptoms are nonspecific

• Symptoms of potential secondary causes should be sought such as sleep apnea, palpitations, muscle weakness, polyuria or polydipsia, use of herbal supplements or other drugs, salt intake, and family history

PHYSICAL EXAM FINDINGS

• Elevated blood pressure using an appropriate-sized cuff, after at least 5 minutes resting in the sitting position with the measurement arm supported at heart level, on 2–3 separate occasions

• Signs of secondary causes should be sought:

  • – Flank bruits (renovascular)

  • – Diminished femoral pulses (coarctation of the aorta)

  • – Skin striae, hirsutism, dorsocervical fat accumulation (cortisol excess)

• Eye fundus exam for signs of vascular damage

• Cardiac exam for signs of left ventricular hypertrophy or dysfunction

• Neurologic exam for signs of stroke

DIFFERENTIAL DIAGNOSIS

• Pseudo- or white-coat hypertension

• High-output state (eg, marked aortic regurgitation)

• Secondary causes:

  • – Obstructive sleep apnea

  • – Renal parenchymal diseases

  • – Steroid therapy (eg, oral contraceptives, prednisone)

  • – Pheochromocytoma

  • – Coarctation of the aorta

  • – Renal artery stenosis

  • – Cushing’s syndrome

  • – Primary hyperaldosteronism

  • – Chronic alcohol use

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• CBC, urinalysis, electrolytes, creatinine, blood urea nitrogen, glucose, lipids, calcium, and uric acid

ELECTROCARDIOGRAPHY

• Left ventricular hypertrophy

• Left atrial abnormality

IMAGING STUDIES

• Echocardiogram may show left ...