University of Nebraska Medical Center, Omaha, Nebraska, USA.
J Am Soc Echocardiogr. 2011 Dec;24(12):1400-8. doi: 10.1016/j.echo.2011.09.007. Epub 2011 Oct 29.
During a microbubble infusion, guided high-mechanical index impulses from a diagnostic two-dimensional transducer improve microvascular recanalization in acute ST-segment elevation myocardial infarction. The purpose of this study was to further elucidate the mechanism of improved microvascular flow in normal and hyperlipidemic atherosclerotic pigs.
In 14 otherwise normal pigs, acute left anterior descending thrombotic coronary occlusions were created. Pigs subsequently received aspirin, heparin, and half-dose fibrinolytic agent (tenecteplase or tissue plasminogen activator), followed by randomization to either no additional treatment (group I) or a continuous infusion of nontargeted microbubbles and guided high-mechanical index impulses from a three-dimensional transducer (group II). Epicardial recanalization rates, ST-segment resolution, microsphere-derived myocardial blood flow, and ultimate infarct size using myocardial contrast echocardiography were compared. The same coronary thrombosis was created in a set of 12 hypercholesterolemic pigs, which were then treated with the same pharmacologic and ultrasound regimen (group III, n = 6) or the pharmacologic regimen alone (group IV, n = 6).
Epicardial recanalization rates in groups I and II were the same (29%), but peri-infarct myocardial blood flow and ultimate infarct size improved after treatment in group II (P < .01 vs group I). In group III, epicardial recanalization was 100% (vs. 50% in group IV), and there were significant reductions in ultimate infarct size (P = .02 compared with group IV).
Guided high-mechanical index impulses from a diagnostic transducer and nontargeted microbubbles improve peri-infarct microvascular flow in acute ST-segment elevation myocardial infarction, even when epicardial recanalization does not occur.
在微泡输注过程中，来自诊断二维换能器的高机械指数脉冲可改善急性 ST 段抬高型心肌梗死的微血管再通。本研究的目的是进一步阐明在正常和高脂血症性动脉粥样硬化猪中改善微血管血流的机制。
在 14 只正常猪中，急性左前降支血栓性冠状动脉闭塞。随后，猪接受阿司匹林、肝素和半剂量纤维蛋白溶解剂（替奈普酶或组织型纤溶酶原激活剂）治疗，然后随机分为不接受其他治疗（I 组）或接受非靶向微泡连续输注和三维换能器引导的高机械指数脉冲（II 组）。比较心外膜再通率、ST 段分辨率、微球衍生心肌血流和心肌对比超声心动图测量的最终梗死面积。在一组 12 只高胆固醇血症猪中创建相同的冠状动脉血栓，然后用相同的药物和超声方案治疗（III 组，n=6）或仅用药物治疗（IV 组，n=6）。
I 组和 II 组的心外膜再通率相同（29%），但 II 组治疗后梗死周围心肌血流和最终梗死面积改善（P<.01 vs I 组）。在 III 组，心外膜再通率为 100%（IV 组为 50%），最终梗死面积显著缩小（与 IV 组相比，P=.02）。
来自诊断换能器的引导高机械指数脉冲和非靶向微泡可改善急性 ST 段抬高型心肌梗死的梗死周围微血管血流，即使心外膜再通未发生。
