Schanzenbächer P, Liebau G, Deeg P, Kochsiek K
Am J Cardiol. 1983 Mar 1;51(5):712-7. doi: 10.1016/s0002-9149(83)80120-9.
The effect of intravenous and intracoronary nifedipine on coronary sinus blood flow, coronary vascular resistance, and myocardial oxygen consumption was studied in 20 patients with coronary artery disease. An intravenous infusion of 1.0 mg nifedipine resulted in a decrease in mean aortic pressure, an increase in heart rate and coronary blood flow, and no significant change in myocardial, oxygen consumption. In contrast, the intracoronary injection of 0.1 mg nifedipine led to a moderate reduction in mean aortic pressure, no change in heart rate, an increase in coronary blood flow, and a significant reduction in myocardial oxygen consumption. During rapid atrial pacing before and approximately 6 minutes after the intracoronary nifedipine injection, coronary blood flow and myocardial oxygen consumption reached identical levels. Thus, only intracoronary injection of nifedipine increases coronary flow in the presence of reduced myocardial oxygen consumption. After intravenous administration, reflex tachycardia counteracts the direct myocardial effect of nifedipine and the potential oxygen-saving effect of afterload reduction. There is no evidence of a prolonged oxygen-sparing effect after cessation of the immediate effects.
对20例冠心病患者研究了静脉注射和冠状动脉内注射硝苯地平对冠状窦血流量、冠状动脉血管阻力及心肌耗氧量的影响。静脉输注1.0毫克硝苯地平导致平均主动脉压降低、心率和冠状动脉血流量增加，而心肌耗氧量无显著变化。相比之下，冠状动脉内注射0.1毫克硝苯地平使平均主动脉压适度降低、心率无变化、冠状动脉血流量增加，且心肌耗氧量显著降低。在冠状动脉内注射硝苯地平之前及注射后约6分钟进行快速心房起搏时，冠状动脉血流量和心肌耗氧量达到相同水平。因此，仅冠状动脉内注射硝苯地平可在心肌耗氧量降低的情况下增加冠状动脉血流量。静脉给药后，反射性心动过速抵消了硝苯地平对心肌的直接作用以及后负荷降低可能带来的节省氧的作用。没有证据表明在即刻效应停止后存在持久的节省氧的作用。
