Ligation of the left circumflex coronary artery with subsequent MRI and histopathology in rabbits.
Ligation of the left circumflex coronary artery with subsequent MRI and histopathology in rabbits.
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发表时间：
2010-11
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通讯作者：
N. Hu;C. Straub;Aida A Garzarelli;Kyle H Sabey;J. Yockman;D. Bull
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作者：
N. Hu;C. Straub;Aida A Garzarelli;Kyle H Sabey;J. Yockman;D. Bull
本发明提供了一种通过结扎左回旋支冠状动脉以通过使用兔模型模拟心脏缺血的手术方法。结扎后5 min心电图监测心率（平均值±标准差，205 ± 13次/分）较结扎前（170 ± 12次/分）增加，但在结扎后25 min恢复至基线（183 ± 11次/分）。心电图ST段显著抬高和QRS波减少提示心肌梗死进展。MRI显示梗死心脏的射血分数降低了20%。心肌缺血引起的心肌坏死和纤维化的程度导致左心室顺应性和效率降低。Masson三色染色显示蓝染的纤维，呈松散的线状瘢痕组织，分布于左心室内，并向心尖延伸。本研究证明了MRI分析兔心肌梗死模型的可行性。心肌结构，包括决定心脏收缩功能的肌纤维的几何形状，通过使用心脏MRI清楚地显示。在动物模型中了解心肌微观结构的三维排列以及梗死心肌的重塑如何影响心脏功能对于人类心脏病的研究具有重要意义。
Provided is the surgical procedure for ligating the left circumflex coronary artery to simulate heart ischemia by using a rabbit model. Heart rate monitored by electrocardiogram was increased at 5 min after ligation (mean ± SEM, 205 ± 13 bpm) when compared with that before ligation (170 ± 12 bpm), but returned to baseline at 25 min after ligation (183 ± 11 bpm). A marked elevation in the ST segment and reduction of the QRS wave of the electrocardiogram indicated the evolving myocardial infarct. The ejection fraction derived from MRI was decreased by 20% in the infarcted heart. The extent of necrosis and fibrosis in the myocardium due to ischemia led to decreased compliance and efficiency of the left ventricle. Masson trichrome staining showed blue-stained fibrils with the appearance of loose, threadlike scar tissue dispersed transmurally in the left ventricle and extending toward the apex. This study demonstrates the feasibility of MRI analysis of myocardial infarction in a rabbit model. The myocardial architecture, including the geometry of the myofibers which determines the contractile function of the heart, is clearly demonstrated by using cardiac MRI. Understanding the 3-dimensional arrangement of the myocardial microstructure and how remodeling of the infarcted myocardium affects cardiac function in an animal model has important implications for the study of heart disease in humans.