MYOCARDIAL VIABILITY IN CORONARY ARTERY DISEASE AND LEFT VENTRICULAR DYSFUNCTION

冠状动脉疾病和左心室功能障碍的心肌活力

• 批准号: 3858116
• 负责人: R O BONOW
• 金额: --
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3858116
• 关键词: angiography; cardiovascular stress test; coronary disorder; deoxyglucose; exercise; heart circulation; heart disorder diagnosis; heart function; heart imaging /visualization /scanning; human subject; intracardiac pressure; magnetic resonance imaging; myocardial infarction; positron emission tomography; radionuclide diagnosis; rest; single photon emission computed tomography; ventricular hypertrophy

In many patients with coronary artery disease (CAD), impaired left ventricular (LV) function arises on the basis of regionally ischemic or hibernating myocardium rather than irreversibly infarcted myocardium. We have previously demonstrated that thallium-201 scintigraphy (using a stress-redistribution-reinjection protocol) is an accurate method to identify dysfunctional but viable myocardial regions, as verified by evidence of preserved metabolic activity by positron emission tomography (PET) and by improved regional function after myocardial revascularization.These findings have been extended during the past year by 4 series of investigations. 1.) Studies employing gated spin echo magnetic resonance imaging (MRI) to assess regional end-diastolic wall thickness and systolic wall thickening have confirmed that regions identified as viable by thallium uptake have preserved wall thickening. 2.) We have also shown that thallium injected at rest (with imaging initially and after a 4 hour redistribution period) is also a valuable technique for identifying viable myocardium in comparison to the results of both PET and MRI. 3.) We have demonstrated that regions with parallel reduction in blood flow and glucose utilization (as measured by uptake of (18)F-fluorodeoxyglucose, or FDG have preserved wall thickening, as long as the reduction in FDG activity is not severe. Thus, regions with reduced blood flow need not manifest enhanced FDG uptake relative to flow (termed the FDG-blood flow "mismatch") to be identified as viable, and the severity of the metabolic defect must be taken into consideration in the assessment of viable myocardium using PET imaging. 4.) We have shown that regions with reduced FDG uptake with normal regional blood flow (considered a "normal" finding by other investigators) occurs predominantly in regions of jeopardized myocardium capable of undergoing reversible ischemia. The cause of this metabolic defect, leading to reduced rather than enhanced glucose uptake, remains to be clarified.

在许多冠状动脉疾病（CAD）患者中， 心室（LV）功能的产生是基于局部缺血或 冬眠心肌而不是不可逆的梗死心肌。 我们以前已经证明，铊-201层析（使用 应力再分布再注入协议）是一种精确方法， 识别功能障碍但存活的心肌区域，通过 正电子发射断层扫描显示代谢活性保留的证据 (PET)并通过改善心肌梗死后的局部功能 这些发现在过去的一年中得到了扩展 4系列调查。 1.）的人。采用门控自旋回波的研究 磁共振成像（MRI）评估局部舒张末期室壁 厚度和收缩期室壁增厚已经证实， 通过铊吸收鉴定为可行的细胞壁增厚得以保留。 2.）的情况。我们还表明，铊注射在休息（与成像 最初和4小时再分配期后）也是有价值的 与结果相比，用于识别存活心肌的技术 PET和MRI的图像。3.）第三章我们已经证明， 血流量和葡萄糖利用的减少（通过摄取测量 的（18）F-氟脱氧葡萄糖或FDG具有保留的壁增厚， 只要FDG活性的降低不严重。 因此， 血流减少不一定表现出相对于血流的FDG摄取增强 （称为FDG-血流“不匹配”）被确定为可行，以及 必须考虑代谢缺陷的严重性， 使用PET成像评估存活心肌。4.）我们已经表明 FDG摄取减少的区域血流正常 （其他研究者认为是“正常”发现） 主要是在能够经受 可逆性缺血 这种代谢缺陷的原因，导致 减少而不是增强葡萄糖摄取的情况仍有待澄清。