Packer M, Meller J, Medina N, Yushak M
Am J Cardiol. 1983 Jan 1;51(1):183-8. doi: 10.1016/s0002-9149(83)80033-2.
The hemodynamic effects of oral captopril and intravenous nitroprusside were compared in 15 patients with severe chronic congestive heart failure. At doses of both drugs titrated so as to produce similar decreases in systemic vascular resistance in each patient, nitroprusside produced substantially greater increases in cardiac index (+0.67 versus +0.31 liters/min/m2, p less than 0.01) but smaller decreases in mean arterial pressure (-18.4 versus -11.0 mm Hg, p less than 0.01) than did captopril. This finding was due to a significant decrease in heart rate with captopril (-7 beats/min, p less than 0.01) which was not seen with nitroprusside, since changes in stroke volume index with both drugs were similar. Nitroprusside produced a decrease in pulmonary arteriolar resistance quantitatively similar to the decrease in systemic vascular resistance, but the decrease in pulmonary arteriolar resistance with captopril was not significant. Despite similar decreases in systemic resistance, captopril produced a greater decrease in left ventricular filling pressure (-10.2 versus -6.9 mm Hg, p less than 0.01) but a smaller decrease in mean right atrial pressure (-3.1 versus -5.3 mm Hg, p less than 0.01) than did nitroprusside. Thus, captopril has actions independent of its systemic vasodilator effects which account for the quantitative differences observed in its hemodynamic responses compared with those of nitroprusside in patients with severe chronic heart failure. These differences support experimental evidence that angiotensin, in addition to its direct systemic arterial vasoconstrictor actions, exerts positive chronotropic effects and alters ventricular compliance but has minimal direct effects on the limb venous circulation and on the pulmonary vasculature.
对15例严重慢性充血性心力衰竭患者比较了口服卡托普利和静脉滴注硝普钠的血流动力学效应。在滴定两种药物剂量以使每位患者的体循环血管阻力产生相似降低的情况下，硝普钠使心脏指数显著增加更多（+0.67对+0.31升/分钟/平方米，p<0.01），但使平均动脉压降低幅度更小（-18.4对-11.0毫米汞柱，p<0.01），与卡托普利相比。这一发现是由于卡托普利使心率显著降低（-7次/分钟，p<0.01），而硝普钠未出现这种情况，因为两种药物的每搏量指数变化相似。硝普钠使肺小动脉阻力降低的程度与体循环血管阻力降低程度在数量上相似，但卡托普利使肺小动脉阻力降低不显著。尽管体循环阻力降低相似，但卡托普利使左心室充盈压降低幅度更大（-10.2对-6.9毫米汞柱，p<0.01），但使平均右心房压降低幅度更小（-3.1对-5.3毫米汞柱，p<0.01），与硝普钠相比。因此，卡托普利具有独立于其体循环血管扩张作用的效应，这解释了在严重慢性心力衰竭患者中观察到的其血流动力学反应与硝普钠相比的数量差异。这些差异支持了实验证据，即血管紧张素除了其直接的体循环动脉血管收缩作用外，还发挥正性变时作用并改变心室顺应性，但对肢体静脉循环和肺血管系统的直接作用最小。
