摘要
背景:既往认为心电图(ECG)上出现Q波是陈旧性心肌梗死(MI)的标志,但这一观点的准确性尚不确定。本研究的目的是用新的诊断标准来检验ECG诊断陈旧性心肌梗死的准确性。方法:该研究采用回顾性方式纳入研究对象,由来自同一机构的独立设盲评估者重新分析ECG以及心脏磁共振(CMR)结果。
Background: The presence of Q waves in the electrocardiogram(ECG) has been used as a marker of prior myocardial infarction(MI). Its accuracy, however, is uncertain. The purpose of this study is to determine the accuracy of an ECG to detect prior MI compared with a novel criterion standard. Methods: This study conducted retrospective inclusion with de novo analysis of ECG and cardiac magnetic resonance(CMR) by independent blinded readers in a single-institution setting. The population consisted of a consecutive sample of 146 patients referred for CMR for evaluation of myocardial viability and necrosis. Q/QS waves on ECG were defined as per Minnesota Code criteria. Myocardial scar was quantified and localized by CMR delayed contrast hyperenhancement and assumed as criterion standard. Sensitivity, specificity, and predictive values of ECG were calculated for different scar sizes(>1%, >15%, and >30%of the myocardium) and location(global, anterior, inferior, and lateral walls). Results: Sensitivity was 48.4%; specificity, 83.5; positive predictive accuracy, 72.0%; and negative predictive accuracy, 64.2%. Sensitivity improved when only large infarcts were considered(64.2%), but specificity decreased to 72.7%. Sensitivity for detecting isolated anterior or inferior wall scars was similar, but isolated lateral wall scar was rarely identified(14.3%). When all 3 walls were involved, sensitivity was still low at 57.9%. Conclusions: The lack of sensitivity and the resulting low negative predictive value of Q/QS criteria seriously limit its accuracy as a marker of prior MI.
