MYOCARDIAL VIABILITY--NUCLEAR TECHNIQUES

可逆（缺血性）和轻中度不可逆（非缺血性） 铊缺陷代表具有存活心肌的区域。 以来 仅仅存在存活心肌并不一定表明缺血 心肌，我们研究了应激诱导的可逆铊 缺陷在预测功能恢复方面更准确， 与非缺血但存活心肌相比的血运重建 （轻度-中度不可逆铊缺陷）。 我们研究了11名患者 患有慢性冠状动脉疾病的患者， 血运重建后定量应力再分布再注射 门控磁共振成像（MRI）和放射性核素 动脉造影 静息时平均LV射血分数从31 血运重建前± 8%至38 ± 11% 血运重建后（P <0.05）。 两到四次核磁共振和轴向铊 对每个患者的切片进行匹配和分析。 对于每个切片， 对血管重建后收缩期室壁增厚进行了目视评估， MRI的5个区域。 在总共137个血运重建区域中，62个区域 血管重建前室壁运动异常，其中42例改善 20例无改善。 在42例异常中， 血管重建后改善的区域，21个（50%）显示 可逆性铊缺陷，仅2例轻度-中度不可逆性 缺陷 相比之下，在20个没有改善的异常区域中， 血运重建后，14例（70%）显示轻中度不可逆性 只有3例具有可逆性铊缺陷（p <0.0001）。 这些 数据表明，在进行压力研究时，大多数轻度-中度压力 不可逆的铊区域代表了一种混合物， （非缺血性）和瘢痕心肌可能不会改善 再血管化后。 另一方面， 在失能区中的应力上的可逆铊缺陷更多 准确预测血运重建后的功能恢复。

Reversible (ischemic) and mild-moderate irreversible (nonischemic) thallium defects represent regions with viable myocardium. Since the mere presence of viable myocardium does not necessarily indicate ischemic myocardium, we investigated whether stress-induced reversible thallium defects are more accurate in predicting recovery of function after revascularization compared to nonischemic but viable myocardium (mild-moderate irreversible thallium defects). We studied 11 patients with chronic coronary artery disease who underwent pre- and post-revascularization quantitative stress-redistribution-reinjection thallium, gated magnetic resonance imaging (MRI) and radionuclide angiography. Mean LV ejection fraction at rest increased from 31 plus/minus 8% pre-revascularization to 38 plus/minus 11% post-revascularization (p<0.05). Two to four MRI and thallium transaxial slices were matched and analyzed per patient. For each slice, pre- and post-revascularization systolic wall thickening was visually assessed in 5 regions by MRI. From a total of 137 revascularized regions, 62 regions had abnormal wall motion pre-revascularization, of which 42 improved post-revascularization and 20 did not improve. Among the 42 abnormal regions which improved post-revascularization, 21 (50%) exhibited reversible thallium defects and only 2 had mild-moderate irreversible defects. In contrast, of the 20 abnormal regions that did not improve post-revascularization, 14 (70%) demonstrated mild-moderate irreversible defects and only 3 had reversible thallium defects (p<0.0001). These data suggest that when performing stress studies, most mild-moderate irreversible thallium regions represent an admixture of viable (nonischemic) and scarred myocardium that may not improve post-revascularization. On the other hand, the identification of reversible thallium defect on stress in an asynergic region more accurately predicts recovery of function after revascularization.