MRI OF COLLATERAL DEVELOPMENT IN THE HEART

描述(摘自申请者摘要)：在缺血性心脏病中 侧支循环的存在和范围可以预防心肌梗死 或至少限制损害，缩小梗塞面积。这个 这项建议的目的是描述冠状动脉病变的发展 基于磁共振成像方法的心脏络脉研究 (核磁共振)。基于MRI的侧枝生长测量可以定义功能性 络脉保护心肌血流量和收缩的能力 在有梗死风险的区域发挥作用。这将是一个意义重大的 比目前用来确定血管病变范围的血管造影方法更具优势 心脏的侧支循环。拟议的研究还将确定 心脏的侧支发育在多大程度上会转化为 心脏防止应激引起的缺血的能力。这些研究将是 在实验动物模型中进行侧支发育缓慢 冠状动脉左回旋支进行性闭塞(‘ameroid 蛇的模型)。这种间接发展的动物模型近似于 人类发生的冠状动脉疾病的进展。建议数 评价心脏侧支循环血流的MRI诊断技术 未来可能会改善对结果的预测。了解如何 抵押品增长可以非侵入性地跟踪，也意味着可以评估 更有效的促进心脏侧支循环发展的新疗法 并能显著改变冠状动脉疾病的自然病史。

DESCRIPTION (Adapted from Applicants Abstract): In ischemic heart disease the presence and extent of collateral circulation can prevent myocardial infarction, or at least limit the damage and reduce the size of infarcts. The objective of this proposal is to characterize the development of coronary collaterals in the heart with methods based on magnetic resonance imaging (MRI). MRI-based measures of collateral growth can define the functional capacity of collaterals to preserve myocardial blood flow and contractile function in regions at risk of infarction. This would be a significant advantage over current angiographic methods used to define the extent of collateral circulation in the heart. The proposed studies will also determine to what degree collateral development in heart translates into an increased capacity of the heart to prevent stress-induced ischemia. The studies will be carried out in an experimental animal model of collateral development with slow progressive occlusion of the left circumflex coronary artery ('ameroid constrictor' model). This animal model of collateral development approximates the progression of coronary artery disease as it occurs in humans. The proposed diagnostic MRI techniques for assessment of collateral blood flow in the heart may in the future allow improved prediction of outcome. Understanding how collateral growth can be followed non-invasively also means that one can assess more effectively new therapies that boost collateral development in the heart and which could markedly change the natural history of coronary artery disease.