Travill C M, Pugh S, Noble M I
Charing Cross and Westminister Medical School, Department of Cardiology, Charing Cross Hospital, London, England.
Clin Ther. 1994 Sep-Oct;16(5):783-92.
Milrinone is an inotropic and vasodilator agent proven to be effective in the treatment of heart failure. This study evaluated whether milrinone produces inotropic and hemodynamic effects independent of reflex adrenergic stimulation. Eleven stable heart failure patients (New York Heart Association class II to III) undergoing cardiac catheterization received intravenous (i.v.) milrinone (50 micrograms/kg for 10 minutes followed by 0.5 micrograms/kg/min for 50 minutes) during beta-adrenergic blockade. After beta-blockade with a 50-mg oral dose of metoprolol, heart rate decreased by a mean of 16.6%. The peak inotropic response to i.v. milrinone measured using the maximum rate of rise of left ventricular pressure (LV dP/dt) was fully developed at 20 minutes. Mean absolute inotropic response of LV dP/dt from baseline was statistically significant at 10, 20, 30, and 40 minutes (P < 0.05). Mean percentage increase in cardiac index from baseline was statistically significant at 20 and 30 minutes, and mean absolute decline from baseline for pulmonary capillary wedge pressure was statistically significant at 20 and 40 minutes (P < 0.05). The inotropic and hemodynamic effects of i.v. milrinone were thus preserved during beta-adrenergic blockade. This finding is consistent with a mechanism of action of i.v. milrinone--myocardial phosphodiesterase inhibition--that is independent of reflex adrenergic stimulation.
米力农是一种正性肌力和血管扩张剂，已被证明对治疗心力衰竭有效。本研究评估了米力农是否能产生独立于反射性肾上腺素能刺激的正性肌力和血流动力学效应。11名接受心脏导管插入术的稳定心力衰竭患者（纽约心脏协会II至III级）在β肾上腺素能阻滞剂治疗期间接受静脉注射米力农（50微克/千克，持续10分钟，随后以0.5微克/千克/分钟的速度持续50分钟）。口服50毫克美托洛尔进行β受体阻滞剂治疗后，心率平均下降16.6%。使用左心室压力最大上升速率（LV dP/dt）测量的静脉注射米力农的峰值正性肌力反应在20分钟时完全显现。在10、20、30和40分钟时，LV dP/dt相对于基线的平均绝对正性肌力反应具有统计学意义（P<0.05）。心脏指数相对于基线的平均百分比增加在20和30分钟时具有统计学意义，肺毛细血管楔压相对于基线的平均绝对下降在20和40分钟时具有统计学意义（P<0.05）。因此，静脉注射米力农的正性肌力和血流动力学效应在β肾上腺素能阻滞剂治疗期间得以保留。这一发现与静脉注射米力农的作用机制——心肌磷酸二酯酶抑制——一致，该机制独立于反射性肾上腺素能刺激。
