Vasodilatory beta-blockers: systemic and regional hemodynamic effects

The systemic and regional hemodynamic alterations in hypertension and of the beta-adrenergic receptor inhibiting agents are reviewed. Hemodynamically, hypertension may be regarded as persistent elevation of arterial pressure associated with increased total peripheral resistance. In early or mild essential hypertension, however, increased total peripheral resistance may not readily be recognized because of the overriding effect of increased cardiac output. Clearly, the hemodynamics of blood pressure control are complex, and the mechanisms of antihypertensive agents must be used appropriately. The early beta-blockers reduced heart rate and cardiac output immediately after intravenous administration without immediately reducing arterial pressure, and calculated total peripheral resistance was increased. With prolonged oral treatment, arterial pressure decreased while maintaining a reduced heart rate and cardiac output. Total peripheral resistance, however, remained elevated. Recent beta-blockers, such as celiprolol, provide an improved physiologic response by instantly reducing arterial pressure and total peripheral resistance without reducing heart rate or cardiac output or expanding intravascular volume.