Hemodynamic and cardiac adaptation in essential hypertension. Consequences for therapy.
In so-called essential hypertension, at least three different subsets of pathophysiologic findings can be identified: mild hypertension in nonobese juvenile subjects characterized by elevated cardiac output, normal peripheral resistance, increased sympathetic activity as measured by norepinephrine and plasma renin activity; hypertension in the elderly with a low cardiac output, often with left ventricular hypertrophy, elevated total peripheral resistance, nephrosclerosis contracted intravascular volume, and low plasma renin activity; and obese hypertensive patients with a high cardiac output, expanded intravascular volume, and a normal total peripheral resistance. Although there is often an overlap among these three entities, antihypertensive treatment can easily be adapted accordingly. A beta-adrenoreceptor blocker is the step-one drug to be used in mild hypertension with an elevated cardiac output. The drug's negative inotropic and chronotropic properties will bring the elevated cardiac output and heart rate back to normal. In the elderly hypertensive patient, an arteriolar and venous vasodilator, such as an antiadrenergic agent, slow channel calcium blocker, or a converting enzyme inhibitor, will lower total peripheral resistance and unburden the left ventricle. In the obese patient and also in most black subjects, the first-step antihypertensive agent remains a thiazide diuretic. Labetalol, an agent with both beta- and alpha-adrenoreceptor properties, shows promise for the treatment of hypertension in the young as well as in the older patient. It seems to be the agent of choice in patients with established essential hypertension who are concomitantly suffering from coronary artery disease.
D000222:Adaptation, Physiological; D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000375:Aging; D044383:Black People; D005117:Cardiac Complexes, Premature / Q000209:etiology; D002302:Cardiac Output; D006332:Cardiomegaly / Q000150:complications; D003327:Coronary Disease / Q000503:physiopathology; D004232:Diuretics / Q000627:therapeutic use; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D007741:Labetalol / Q000627:therapeutic use; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology; D010101:Oxygen Consumption; D014665:Vasodilator Agents / Q000627:therapeutic use
D000319:Adrenergic beta-Antagonists; D004232:Diuretics; D014665:Vasodilator Agents; D007741:Labetalol