Man in 't Veld A J, Schalekamp M A
Eur Heart J. 1983 Jul;4 Suppl D:31-41. doi: 10.1093/eurheartj/4.suppl_d.31.
The relevance of intrinsic sympathomimetic activity (ISA) and cardioselectivity for the acute and long-term haemodynamic effects of beta-blocker therapy for hypertension was assessed from reports in the literature. The beta-blockers included in this survey are pindolol, practolol, alprenolol, oxprenolol, acebutolol, penbutolol, metoprolol, atenolol, propranolol and timolol. Forty-four acute and 41 long-term studies in 430 and 482 subjects respectively, were analysed. In acute studies arterial pressure is barely lowered, whereas in spite of the many pharmacological and physicochemical differences beta-blockers appear to have a hypotensive effect of approximately equal magnitude during long-term treatment. In the acute studies, the falls in heart rate, stroke volume, cardiac output and subsequently increased total peripheral resistance are inversely proportional to the pharmacologically defined quantity of ISA of the beta-blockers. The response of vascular resistance to cardiodepression is similar for non-selective and beta 1-selective agents. During long-term therapy, the inverse correlation between cardiac output and vascular resistance is shifted to a lower level of vascular resistance. This reduction of vascular resistance at any level of cardiac output that underlies the hypotensive action of beta-blockers is associated with an increase in stroke volume. Thus, the absolute value of vascular resistance during beta-blocker therapy is determined by the degree of ISA, irrespective of the quality of cardioselectivity. Consequently, beta-blockers with sufficient ISA to prevent disturbance of tissue perfusion at rest reduce the characteristically elevated vascular resistance in longstanding arterial hypertension in contrast with beta-blockers lacking this property. This can have implications for the long-term prognosis of this condition.
根据文献报道，评估了内在拟交感活性（ISA）和心脏选择性对β受体阻滞剂治疗高血压的急性和长期血流动力学效应的相关性。本调查中纳入的β受体阻滞剂有吲哚洛尔、普拉洛尔、阿普洛尔、氧烯洛尔、醋丁洛尔、喷布洛尔、美托洛尔、阿替洛尔、普萘洛尔和噻吗洛尔。分别对430名受试者的44项急性研究和482名受试者的41项长期研究进行了分析。在急性研究中，动脉压几乎没有降低，而尽管存在许多药理和物理化学差异，但β受体阻滞剂在长期治疗期间似乎具有大致相同程度的降压作用。在急性研究中，心率、每搏量、心输出量的下降以及随后总外周阻力的增加与β受体阻滞剂药理学定义的ISA量成反比。非选择性和β1选择性药物对血管阻力对心脏抑制的反应相似。在长期治疗期间，心输出量与血管阻力之间的负相关关系转移到较低水平的血管阻力。β受体阻滞剂降压作用所基于的在任何心输出量水平下血管阻力的降低与每搏量的增加有关。因此，β受体阻滞剂治疗期间血管阻力的绝对值由ISA程度决定，与心脏选择性的性质无关。因此，与缺乏这种特性的β受体阻滞剂相比，具有足够ISA以防止静息时组织灌注紊乱的β受体阻滞剂可降低长期动脉高血压中典型升高的血管阻力。这可能对该疾病的长期预后产生影响。
