PERSISTENT REGIONAL WALL MOTION ABNORMALITIES FOLLOWING EXERCISE

运动性心肌梗死后是否发生顿抑 缺血仍然是有争议的。我们研究了17名患有 冠状动脉造影术证实的冠状动脉疾病，所有人都有异常 静息状态下的左心室射血分数反应(48+/-16%) 核素血管造影术评估运动(44+/-15%)。17个人中的一个 2例，5例还进行了使用Rb的心肌血流研究 正电子发射断层扫描(PET)。每名患者，4套 在休息时采集放射性核素血管造影术和Rb图像， 在最大仰卧位自行车运动期间，运动后15分钟和30分钟。 计算定量局部射血分数(REF) 左心室感兴趣区分为8个环状扇区。在15年内 在17例患者(88%)中，运动性REF异常的区域有 运动后15分钟REF持续或恶化11例 (65%)运动后30min仍有异常反应。在这些人中 5例REF和心肌血流检查，8个区域显示 运动期间和运动后15分钟REF减少与以下因素相关 与正常区域相比血流量较低。在运动后30分钟， 心肌血流继续跟踪REF，有4个区域 显示REF和血流和4个区域的一致性改善 随着REF和血流量的持续下降。发现了减少的 运动后REF降低区域的心肌血流量变化 不符合顿抑心肌的经典定义。虽然 持续运动后的机制减少 心肌血流量未知，任何一种可归因于 运动中的冠状动脉收缩，即交感神经 系统激活，内皮功能障碍或流体动力收缩， 也可能是运动后的手术。

Whether stunned myocardium occurs after exercise-induced myocardial ischemia remains controversial. We studied 17 patients with angiographically proven coronary artery disease, all of whom had abnormal left ventricular ejection fraction response from rest (48+/-16%) to exercise (44+/-15%) as assessed by radionuclide angiography. Of the 17 patients, 5 also underwent Rubidium myocardial blood flow study using positron emission tomography (PET). For each patient, 4 sets of radionuclide angiography and Rubidium images were acquired at rest, during maximal supine bicycle exercise, 15 min and 30 min post-exercise. Quantitative regional ejection fraction (REF) was assessed by dividing the left ventricular region of interest into 8 annular sectors. In 15 of 17 patients (88%), regions with abnormal exercise-induced REF had persistent or worsening of REF at 15 min post-exercise and in 11 patients (65%) the abnormal response persisted at 30 min post-exercise. Among the 5 patients with REF and myocardial blood flow studies, 8 regions showed decreased REF during exercise and 15 min post-exercise associated with lower blood flow compared to normal regions. At 30 min post-exercise, myocardial blood flow continued to track REF, with 4 regions demonstrating concordant improvement in REF and blood flow and 4 regions with persistent decrease in REF and blood flow. The finding of decreased myocardial blood flow in regions with decreased REF post-exercise does not conform to the classic definition of stunned myocardium. Although the mechanisms responsible for persistent post-exercise decrease in myocardial blood flow is unknown, any one of the ascribed causes of coronary artery vasoconstriction during exercise i.e sympathetic nervous system activation, endothelial dysfunction or hydrodynamic constriction, may also be operative post-exercise.