MRI OF COLLATERAL DEVELOPMENT IN THE HEART

描述（改编自申请人摘要）：在缺血性心脏病中， 侧支循环的存在和程度可以防止心肌 或者至少限制损伤并减小梗塞的大小。的 本提案的目的是描述冠状动脉病变的发展特征， 用磁共振成像的方法检查心脏的侧枝 （MRI）。基于MRI的侧支生长测量可以定义功能性 络脉维持心肌血流和收缩的能力 在有梗死风险的区域发挥作用。这将是一个重大的 与目前用于定义血管造影程度的方法相比， 心脏的侧支循环拟议的研究还将确定 心脏侧支血管的发展在多大程度上转化为 心脏防止压力引起的局部缺血的能力。这些研究将 在侧支发育缓慢的实验动物模型中进行 冠状动脉左回旋支的进行性闭塞（“ameroid 压缩机模型）。这种侧枝发育的动物模型近似于 冠状动脉疾病的进展，因为它发生在人类。拟议 用于评估心脏侧支血流的诊断MRI技术 在未来可能会改善对结果的预测。了解如何 侧支生长可以被非侵入性地跟踪也意味着人们可以评估 更有效地促进心脏侧支发育的新疗法 并且可以显著改变冠状动脉疾病的自然病程。

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.