In search of the arrhythmogenic grey zone within myocardial scar using late gadol

描述（由申请人提供）：室性心动过速（VT）和纤颤（VF）是冠状动脉疾病（CAD）患者心源性猝死（SCD）的主要原因。VT/VF的来源被认为是瘢痕心肌内的致心律失常底物，造成易发生再入性室性心动过速的区域。晚期钆增强（LGE）心血管MR （CMR）是体内鉴定心肌瘢痕的无创金标准，但其在VT患者治疗或风险分层中的临床价值尚不确定。LGE CMR已被用于识别含有活细胞和纤维化混合（组织异质性）的区域，称为“灰色地带”（GZ）。“梗死周围区”或“心律失常边界区”)。大量研究表明，GZ的体积比疤痕的体积更能预测室性心动过速和心律失常死亡的诱发性。我们的假设是，更准确地识别GZ是可能的，并将增加LGE预测心律失常的能力，对SCD进行风险分层，并确定室性心动过速消融的心律失常边界区。我们建议使用高空间分辨率LGE来解析复杂的疤痕形态，并使用T1- mapping来定量识别GZ。相反对比LGE， GZ亮而疤痕暗，突出了疤痕核心的GZ。CMR方法将更好地对GZ进行分类，并将应用于动物研究中进行组织病理学相关性研究，以及对VT患者的初步研究。

DESCRIPTION (provided by applicant): Ventricular tachycardia (VT) and fibrillation (VF) are a major cause of sudden cardiac death (SCD) in those with coronary artery disease (CAD). The source of VT/VF is believed to be the arrhythmogenic substrate within scarred myocardium, creating areas prone to reentrant ventricular tachyarrhythmia. Late gadolinium enhancement (LGE) cardiovascular MR (CMR) is the non-invasive gold standard for in-vivo identification of myocardial scar, but its clinical value in treatment or risk stratifying VT patients remains uncertain. LGE CMR has been employed to identify areas which contain a mixture of living cells and fibrosis (tissue heterogeneity), called the 'grey zone' (GZ) (a.k.a. 'peri-infarct zone' or 'arrhythmic border zone'). Numerous studies have shown that the volume of GZ, much more powerfully than the volume of scar, predicts inducibility of VT and arrhythmic death. Our hypothesis is that more accurate identification of GZ is possible, and will increase the power of LGE to predict arrhythmia, risk-stratify for SCD, and identify the arrhythmic border zone for VT ablation. We propose using high spatial resolution LGE to resolve complex scar morphology, and T1- mapping for quantitative identification of GZ. Reverse-contrast LGE, by which GZ is bright and scar is dark, highlights GZ within the scar core. The CMR methods to better classify GZ will be applied to an animal study for histopathological correlation, and a pilot study of VT patients. PUBLIC HEALTH RELEVANCE: Ventricular tachycardia is a common arrhythmia, responsible for almost half of deaths due to heart-disease. The cause of the arrhythmia is often scar in the heart muscle after a heart-attack, which changes the electrical signals within the heart. We will study ways to use cardiac MRI to detect scar in the heart which may result in an arrhythmia.