Fischell T A, Derby G, Tse T M, Stadius M L
Division of Cardiology, Stanford University Medical Center, CA 94305.
Circulation. 1988 Dec;78(6):1323-34. doi: 10.1161/01.cir.78.6.1323.
To determine whether percutaneous transluminal coronary angioplasty (PTCA) increases coronary artery luminal dimensions by stretching and injuring ("paralyzing") the smooth muscle of the arterial wall, we prospectively analyzed spontaneous changes and then intracoronary nitroglycerin-induced changes in segmental coronary artery diameters during the first 30 minutes after uncomplicated single-vessel PTCA in 10 patients. Five additional patients received intravenous nitroglycerin throughout the procedure to determine whether nitroglycerin could prevent vasoconstriction after PTCA. All of the patients were maintained on oral doses of diltiazem and aspirin at the time of the study. Coronary arteriography was performed at 2, 5, 15, and 30 minutes after PTCA and then 3 minutes after 300 micrograms i.c. nitroglycerin. Quantitative measurements (computerized edge-detection) were performed at each time, in coronary segments centered in the dilated segment, distal to the dilated segment, and in a control vessel not manipulated with the balloon catheter or guidewire. Progressive vasoconstriction (defined as a loss of diameter that was reversed by intracoronary nitroglycerin) was observed after PTCA in the dilated and distal segments (10 of 10 patients) but not in the control segment. The vasoconstriction in the dilated segment at 30 minutes (mean, 30 +/- 4%) was highly statistically significant compared with vasoconstriction at 2 and 5 minutes after PTCA (p less than 0.001) and compared with the control segment at 30 minutes (p less than 0.005). There was no significant loss of diameter after PTCA in the dilated segment in the five patients who received intravenous nitroglycerin. In conclusion, 1) spontaneous coronary artery vasoconstriction after PTCA occurs routinely at and distal to the site of balloon dilatation despite pretreatment with aspirin and calcium channel blockers; 2) coronary artery vasoconstriction after PTCA is rapidly reversed by intracoronary nitroglycerin and can be prevented by the continuous administration of intravenous nitroglycerin during and after the procedure; 3) these results are incompatible with the hypothesis that PTCA improves coronary luminal dimensions by arterial "paralysis"; and 4) these findings have implications concerning the etiology and prophylaxis of abrupt vessel closure after PTCA.
为了确定经皮腔内冠状动脉成形术（PTCA）是否通过拉伸和损伤（“麻痹”）动脉壁平滑肌来增加冠状动脉管腔尺寸，我们前瞻性分析了10例患者在进行无并发症的单支血管PTCA后最初30分钟内冠状动脉节段直径的自发变化以及随后冠状动脉内硝酸甘油诱导的变化。另外5例患者在整个手术过程中接受静脉注射硝酸甘油，以确定硝酸甘油是否能预防PTCA后的血管收缩。研究时所有患者均口服地尔硫䓬和阿司匹林。在PTCA后2、5、15和30分钟以及冠状动脉内注射300微克硝酸甘油后3分钟进行冠状动脉造影。每次在以扩张节段为中心的冠状动脉节段、扩张节段远端以及未用球囊导管或导丝操作的对照血管中进行定量测量（计算机边缘检测）。在PTCA后，扩张节段和远端节段（10例患者中的10例）观察到进行性血管收缩（定义为直径减小，冠状动脉内硝酸甘油可使其逆转），但对照节段未观察到。与PTCA后2分钟和5分钟时的血管收缩相比（p<0.001）以及与30分钟时的对照节段相比（p<0.005），扩张节段在30分钟时的血管收缩（平均30±4%）具有高度统计学意义。接受静脉注射硝酸甘油的5例患者的扩张节段在PTCA后直径无明显减小。总之，1）尽管术前使用了阿司匹林和钙通道阻滞剂，但PTCA后冠状动脉自发血管收缩在球囊扩张部位及其远端经常发生；2）PTCA后的冠状动脉血管收缩可被冠状动脉内硝酸甘油迅速逆转，并且在手术期间和术后持续静脉注射硝酸甘油可预防；3）这些结果与PTCA通过动脉“麻痹”改善冠状动脉管腔尺寸的假说不一致；4）这些发现对PTCA后血管突然闭塞的病因和预防具有重要意义。
