Silke B, Nelson G I, Verma S P, Ahuja R C, Okoli R C, Hussain M, Taylor S H
Herz. 1984 Feb;9(1):57-64.
The relevance of the ancillary pharmacological properties of intrinsic sympathomimetic activity (ISA) and cardioselectivity to the haemodynamic profile following intravenous beta-blockade was examined in a randomised study of propranolol (16 mg), acebutolol (160 mg) or penbutolol (4 mg) in 30 patients with stable angina pectoris. Haemodynamic measurements were undertaken at rest and during four minutes steady-state supine bicycle exercise (25 to 50 W), load limited to the angina threshold, before and after each drug. The randomised groups were statistically similar for major haemodynamic and clinical variables. The plasma concentrations achieved for each drug were in the therapeutic range. At rest, propranolol resulted in greater reductions in resting cardiac output and greater increase in pulmonary artery occluded pressure compared with acebutolol and penbutolol. During the sympathetic stimulus of dynamic exercise, penbutolol resulted in less depression of exercise cardiac performance than either acebutolol or propranolol. These observations are compatible with previous studies which suggested that the possession of ISA by a beta-blocking drug offset the depression of cardiac performance following intravenous beta-blockade; the benefits of ISA on haemodynamic profile appeared maximum at rest and were reduced or abolished during dynamic exercise.
在一项针对30例稳定型心绞痛患者的随机研究中，对内在拟交感活性（ISA）和心脏选择性的辅助药理学特性与静脉注射β受体阻滞剂后的血流动力学特征之间的相关性进行了研究，比较了普萘洛尔（16 mg）、醋丁洛尔（160 mg）或喷布洛尔（4 mg）的效果。在每次用药前和用药后，于静息状态以及在四分钟稳态仰卧位自行车运动（25至50瓦）期间（负荷限制在心绞痛阈值）进行血流动力学测量。随机分组在主要血流动力学和临床变量方面具有统计学相似性。每种药物达到的血浆浓度均在治疗范围内。静息时，与醋丁洛尔和喷布洛尔相比，普萘洛尔导致静息心输出量的降低幅度更大，肺动脉闭塞压的升高幅度更大。在动态运动的交感神经刺激期间，喷布洛尔导致的运动心脏功能抑制比醋丁洛尔或普萘洛尔更小。这些观察结果与先前的研究一致，先前的研究表明β受体阻滞剂具有ISA可抵消静脉注射β受体阻滞剂后心脏功能的抑制；ISA对血流动力学特征的益处似乎在静息时最大，而在动态运动期间则降低或消失。
