MYOCARDIAL VIABILITY IN CORONARY ARTERY DISEASE AND LEFT VENTRICULAR DYSFUNCTION

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。 然而，这种潜在的不可逆的LV功能障碍的识别 一直是个问题许多运动引起的铊-201缺陷并不 在随后的休息再分配图像上正常化，即使当 下层心肌有活力我们已经证明， TL-201在休息后立即标准4小时重新分配图像 促进T1 -201的晚期摄取，并区分存活的和存活的T1 - 201。 心肌梗塞我们研究了100例慢性CAD患者。为260 运动时心肌节段异常者85例（33%）， 在再分配研究中异常。然而，这些缺陷中有42个（49%） 在TI-201再注射后显示出改善或正常的摄取。的 再注射后Tl-201的晚期摄取代表存活心肌， 在3个患者亚组中得到证实。1)在20例患者中重新研究3-6 血运重建后3个月，改善了室壁运动， 在87%的具有“不可逆”缺陷的节段中观察到流动， 再分布研究通过Tl-201再注射确定为可行， 血运重建;这种改善发生在没有被确定为 伤疤。2)在12例磁共振成像研究的患者中， 通过该方法鉴定为存活的具有正常程度的收缩壁 增厚，明显大于被确定为疤痕的区域。第三章 在使用18 F-氟脱氧葡萄糖（FDG）进行PET成像的16名患者中， 具有TI-201缺陷的段通过再注入被识别为可行的， 心肌存活的代谢证据。之间的一致性 Tl-201再注射和FDG摄取数据非常好，51%的区域 严重的“不可逆的”缺陷被两种技术识别为可行的。 这些数据表明，Tl-201回注是一种方便、相对 一种廉价的方法来识别慢性心肌梗死患者的存活心肌 CAD和LV功能障碍。

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. However, the identification of such potentially irreversible LV dysfunction has been problematic. Many exercise-induced thallium-201 defects do not normalize on subsequent resting redistribution images, even when the underlying myocardium is viable. We have demonstrated that reinjection of Tl-201 at rest immediately after the standard 4-hour redistribution image facilitates late uptake of Tl-201 and distinguishes between viable and infarcted myocardium. We studied 100 patients with chronic CAD. Of 260 abnormal myocardial segments during exercise, 85 (33%) were irreversibly abnormal on the redistribution study. However, 42 of these defects (49%) demonstrated improved or normal uptake after TI-201 reinjection. That the late uptake of Tl-201 after reinjection represents viable myocardium is substantiated in 3 subgroups of patients. 1) In 20 patients restudied 3-6 months after revascularization, improved wall motion and improved blood flow was observed in 87% of segments with "irreversible" defects on redistribution studies identified as viable by Tl-201 reinjection before revascularization; such improvement occurred in no segment identified as scar. 2) In 12 patients studied by magnetic resonance imaging, segments identified as viable by this method had a normal degree of systolic wall thickening, significantly greater than the regions identified as scar. 3) In 16 patients studied by PET imaging with 18F-fluorodeoxyglucose (FDG), segments with TI-201 defects identified as viable by reinjection had metabolic evidence for myocardial viability. The concordance between the Tl-201 reinjection and FDG uptake data was excellent, with 51% of regions with severe "irreversible" defects identified as viable by both techniques. These data indicate that Tl-201 reinjection is a convenient and relatively inexpensive method to identify viable myocardium in patients with chronic CAD and LV dysfunction.