Goldstein J A, Butterfield M C, Ohnishi Y, Shelton T J, Corr P B
Department of Medicine, Washington University School of Medicine, St Louis, MO 63198.
Circulation. 1994 Jul;90(1):139-47. doi: 10.1161/01.cir.90.1.139.
Patients with acute coronary artery thrombosis often develop primary malignant ventricular arrhythmias (MVA) early after coronary occlusion. In contrast, acute ischemia induced by nonthrombotic balloon occlusion during routine coronary angioplasty rarely elicits such arrhythmias. This study was designed to assess the role of intracoronary thrombosis in arrhythmogenesis during acute ischemia.
We compared the incidence of MVA associated with acute left anterior descending coronary artery (LAD) thrombosis elicited in open-chest anesthetized dogs by electrical injury (n = 10) or intracoronary stent (n = 9) versus LAD balloon occlusion (n = 15). Compared with animals subjected to balloon occlusion, those with thrombotic occlusion had a significantly greater incidence of MVA, defined as nonsustained ventricular tachycardia (total duration > 10 seconds), sustained ventricular tachycardia, or ventricular fibrillation developing within the first 30 minutes of occlusion. In the combined thrombosis groups, MVA developed in 11 of 19 animals (58%) (6 of 10 dogs with electrical injury and 5 of 9 stent animals). In contrast, MVA occurred in only 1 of 15 animals (7%) subjected to balloon occlusion. This striking and significant difference in arrhythmias occurred despite the fact that radioactive microsphere perfusion analysis documented that the extent of left ventricular myocardium rendered ischemic was equal in all groups (percent of left ventricular myocardium with occlusion flow < or = 50% of baseline: electrical injury, 25.2 +/- 5.3%; stent, 27.1 +/- 3.6%; balloon, 34.3 +/- 11.6%; P = NS). Furthermore, there were no differences between the animals with thrombosis or balloon occlusion with respect to changes in echocardiographic parameters of left ventricular function, aortic pressure, or heart rate after occlusion.
These data provide evidence that despite equal magnitudes of jeopardized myocardial mass, acute ischemia induced by thrombotic coronary occlusion results in a greater incidence of MVA than does nonthrombotic balloon occlusion. These findings suggest that the process of intracoronary thrombosis itself exerts arrhythmogenic effects above and beyond the impact of ischemia on myocardium induced by coronary occlusion.
急性冠状动脉血栓形成的患者常在冠状动脉闭塞后早期发生原发性恶性室性心律失常（MVA）。相比之下，在常规冠状动脉血管成形术期间，非血栓性球囊闭塞所诱发的急性缺血很少引发此类心律失常。本研究旨在评估冠状动脉内血栓形成在急性缺血期间心律失常发生中的作用。
我们比较了在开胸麻醉犬中，由电损伤（n = 10）或冠状动脉内支架（n = 9）诱发的急性左前降支冠状动脉（LAD）血栓形成与LAD球囊闭塞（n = 15）相关的MVA发生率。与接受球囊闭塞的动物相比，血栓性闭塞的动物发生MVA的发生率显著更高，MVA定义为非持续性室性心动过速（总持续时间> 10秒）、持续性室性心动过速或在闭塞的最初30分钟内发生心室颤动。在合并的血栓形成组中，19只动物中有11只（58%）发生了MVA（10只电损伤犬中有6只，9只支架置入动物中有5只）。相比之下，接受球囊闭塞的15只动物中只有1只（7%）发生了MVA。尽管放射性微球灌注分析表明所有组中左心室心肌缺血的程度相同（左心室心肌闭塞血流<或=基线的50%的百分比：电损伤，25.2±5.3%；支架，27.1±3.6%；球囊，34.3±11.6%；P =无显著性差异），但心律失常仍存在这一显著差异。此外，在血栓形成或球囊闭塞的动物之间，闭塞后左心室功能、主动脉压力或心率的超声心动图参数变化没有差异。
这些数据表明，尽管心肌受损程度相同，但血栓性冠状动脉闭塞所诱发的急性缺血比非血栓性球囊闭塞导致MVA的发生率更高。这些发现表明，冠状动脉内血栓形成过程本身除了对冠状动脉闭塞所诱发的心肌缺血产生影响外，还具有致心律失常作用。
