Malacoff R F, Lorell B H, Mudge G H, Holman B L, Idoine J, Bifolck L, Cohn P F
Circulation. 1982 Jan;65(1 Pt 2):I32-7.
Nifedipine inhibits the slow-channel calcium current, which plays a major role in vascular smooth-muscle contraction. However, the effect of nifedipine on regional myocardial blood flow (RMBF) in patients with coronary artery disease (CAD) is unknown. In 18 patients with chest pain syndromes, RMBF was determined with xenon-133 before and after nifedipine. In patients with CAD. 25 regions were analyzed distal to significant coronary obstruction(greater than 70% reduction in luminal diameter) and eight regions were analyzed in patients with normal coronary arteries. In patients with CAD, RMBF increased in 21 of 25 regions (average 17.4 /+- 5.7%,p less than 0.01), but decreased in all eight regions in patients with normal coronary arteries, by an average of 14.4 /+- 2.3% (p less than 0.01). The difference between groups was significant (p less than 0.01). In our patients with CAD, improved RMBF appears to be related to a decrease in coronary vascular tone and suggests a physiologic basis for the beneficial effect of nifedipine in ischemic heart disease.
硝苯地平抑制慢通道钙电流，而慢通道钙电流在血管平滑肌收缩中起主要作用。然而，硝苯地平对冠状动脉疾病（CAD）患者局部心肌血流量（RMBF）的影响尚不清楚。在18例胸痛综合征患者中，在服用硝苯地平前后用氙-133测定了RMBF。在CAD患者中，对严重冠状动脉阻塞（管腔直径减少大于70%）远端的25个区域进行了分析，对冠状动脉正常的患者的8个区域进行了分析。在CAD患者中，25个区域中的21个区域的RMBF增加（平均17.4±5.7%，p<0.01），但冠状动脉正常的患者的所有8个区域的RMBF均下降，平均下降14.4±2.3%（p<0.01）。两组之间的差异具有显著性（p<0.01）。在我们的CAD患者中，RMBF的改善似乎与冠状动脉血管张力的降低有关，并提示硝苯地平对缺血性心脏病有益作用的生理基础。
