MYOCARDIAL VIABILITY--NUCLEAR TECHNIQUES

可逆(缺血)和轻-中度不可逆(非缺血) 铊缺陷代表存活心肌的区域。自.以来 仅有存活心肌的存在并不一定意味着缺血 心肌，我们研究了应激诱导的可逆铊 缺陷对术后功能恢复的预测更为准确 血管重建术与非缺血存活心肌的比较 (轻度-中度不可逆铊缺陷症)。我们研究了11名患者 患有慢性冠状动脉疾病的患者在接受前和术后 血管重建后定量应力-再分布-再注射 铊、门控磁共振成像(MRI)和放射性核素 血管造影术。静息状态下平均左心室射血分数从31 血管重建术前加/减8%至38加/负11% 血运重建后(p&lt；0.05)。两到四个核磁共振和铊的轴位扫描 对每个患者的切片进行匹配和分析。对于每个切片，前和 血管重建术后的收缩期壁增厚在 MRI显示5个区域。在总共137个血运重建区域中，有62个区域 血管重建术前室壁运动异常，其中42例改善 血管重建术后20例无改善。在42名异常患者中 改善血管重建后的区域，21个(50%)显示 可逆转的铊缺陷，仅2例为轻-中度不可逆 缺陷。相比之下，在20个没有改善的异常区域中 血管重建术后，14例(70%)表现为轻-中度不可逆 只有3个有可逆性的铊缺陷(p&lt；0.0001)。这些 数据表明，在进行压力研究时，大多数轻度-中度 不可逆的铊区域代表了可 (非缺血)和有疤痕的心肌可能没有改善 血管重建术后。另一方面，对身份的识别 应力引起的可逆性铊缺陷区 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.