Davis T P, Alexander J, Lesch M
Department of Medicine, Henry Ford Hospital, Detroit, MI 48202.
Prog Cardiovasc Dis. 1993 Nov-Dec;36(3):245-60. doi: 10.1016/0033-0620(93)90017-8.
Patients with acute vascular disorders of the CNS demonstrate an abundance of both rhythm and morphologic changes in their ECG. Of these a few will demonstrate myocardial dysfunction and or damage. The value of the ECG in evaluating and predicting which patients will have myocardial dysfunction or damage is questionable. One would assume the echocardiogram would be of more help than the ECG in identifying patients with myocardial damage; however, little data are available. The reason for the poor correlation between ECG findings and clinical correlates has not been explained to date, but it is possible to postulate a theory. There are two mechanisms that might mediate ECG changes in these patients, ie, autonomic neural stimulation from the hypothalamus or elevated circulating catecholamines. Hypothalamic stimulation may cause ECG changes without associated myocardial damage whereas elevated catecholamines may result in myocardial damage. This might explain why so many patients have ECG changes and very few have demonstrable myocardial damage in general, or ischemic damage in particular. That cardiac antiischemic therapy does not change mortality may relate to the fact that treatment has been directed towards patients with ECG changes, which in turn do not correlate with myocardial damage. Better patient selection for such therapy might rest upon demonstration of wall motion abnormalities on echocardiogram. The weakness of this strategy is that many patients with stroke have preexisting coronary disease and wall motion abnormalities and thus echo findings may only document remote infarction rather than acute ischemia.
患有中枢神经系统急性血管疾病的患者心电图显示出大量节律和形态变化。其中一些患者会出现心肌功能障碍和/或损伤。心电图在评估和预测哪些患者会出现心肌功能障碍或损伤方面的价值值得怀疑。人们可能认为超声心动图在识别心肌损伤患者方面比心电图更有帮助；然而，相关数据很少。迄今为止，心电图表现与临床关联之间相关性较差的原因尚未得到解释，但有可能提出一种理论。有两种机制可能介导这些患者的心电图变化，即来自下丘脑的自主神经刺激或循环中儿茶酚胺升高。下丘脑刺激可能导致心电图变化而无相关心肌损伤，而儿茶酚胺升高可能导致心肌损伤。这或许可以解释为什么总体上有如此多患者出现心电图变化，而很少有患者有可证实的心肌损伤，尤其是缺血性损伤。心脏抗缺血治疗并未改变死亡率，这可能与治疗针对的是心电图有变化的患者这一事实有关，而这些变化又与心肌损伤无关。更好地选择此类治疗的患者可能依赖于超声心动图显示的壁运动异常。该策略的缺点是许多中风患者存在既往冠心病和壁运动异常，因此超声心动图结果可能仅显示陈旧性梗死而非急性缺血。
