未被认知的慢性心梗（UMI）患者相当普遍，死亡率明显高于被认知的冠心病患者，国外目前有研究报道延迟增强MRI（DE-MRI）有助于对此类患者的认知。但DE-MRI检测的心梗瘢痕范围与病理一致性如何？有无假阳性、假阴性存在？产生原因和机制；能否识别慢性心梗灶中与室上性心动过速有关的灰带，识别的机制和灰带组织学成分如何？在慢性心梗患者，局部心肌微循环和心室重塑直接影响患者的将来预后。但目前研究多关注DE-MRI心梗瘢痕的检测，对DE-MRI检测的心梗瘢痕与心室重塑后肌壁厚度及室壁运动、心肌功能改变的相关性；瘢痕形态、部位、大小与重塑后心律失常的风险性、BNP水平、靶血管、局部微循环的相关性等所知很少甚或不明，本项目拟通过猪慢性心梗模型的构建，联合3.0T和258层CT对上述问题进行病理对照研究，从而提高对慢性心梗患者，特别是UMI患者的认知及心脏不良事件的早期预测、促进其预后的改善。

Unrecognized myocardial infarcts（UMI）are quite common in patients with coronary atery disease（CAD）whose morality is significantly higher than patients with recognized myocardial infarcts. Such infarction are usually chronic myocardial infarction. Delayed-enhanced MRI is helpful to the awareness of these chronic myocardial scars.However, there are some issues to be discussed. Is there any differences in the extent of chronic myocardial infarts detected by DE-MRI and pathology? whether the bright area on DE-MRI is myocardial infarcts? Is there any false-positive or false-negative detected by DE-MRI? And why? Whether can DE-MRI distinguish the core and the gray zone of chronic myocardial infarcts? What are pathological ingredients of the gray zone which related to supraventricular tachycardia? The myocardial microcirculation and ventricular remodeling are directly related with future survial in patients with chronic myocardial infarcts. But so far most of DE-MRI studies are only concerned on the detection of myocardial infarcts. The little is known about the affect of chronic myocardial infarcts on ventricular remodeling , for example, the correlations between chronic myocardial scars and the score of wall motion, myocardial function, the risk of arrhythmia,myocardial microcirculation,as well as the BNP levels after left wentricular remodeling . According to swine model with chronic myocardial infarction, we are going to study issues mentioned above, and compared phathological findings. Through our research ,we hope to improve the understanding about chronic myocardial infarcts, and improve the early predictions for adverse cardiac events in patients with myocardia scar, especially in UMI, and guide physians to give timely and effective treatment.