Heal A, Al-Sheikh W, Pefkaros K C, Pina I, Serafini A N, Hourani M
South Med J. 1984 Jul;77(7):843-7. doi: 10.1097/00007611-198407000-00014.
A diagnosis of myocardial infarction (MI) is usually established by the evaluation of clinical symptoms, electrocardiographic changes, and serum enzyme levels, specifically creatine phosphokinase, subunit MB (CK-MB), by electrophoresis. A total of 215 patients were evaluated in this study. One hundred two of them were admitted to the coronary care unit and 113 to the emergency room, where they were screened for possible MIs. The radioimmunoassay (RIA) used in this study determines levels of the CK-MB isoenzyme by detecting the B monomer, which also has 100% cross-reactivity with the CK-BB isoenzyme. The intra-assay coefficients of variability (CVs) for 30 samples were 22% (means = 7.0 ng/ml) and 11% (means = 47.3 ng/ml), and the interassay CVs for 30 samples were 17% (means = 7.1 ng/ml) and 9.2% (means = 49.3 ng/ml). Of the 215 patients evaluated, 21 had myocardial infarction by the criteria in the study. The diagnostic sensitivity, specificity, and accuracy were 100.0%, 92.8%, and 93.5% respectively. These values increased to 100.0%, 96.9%, and 97.2% when only coronary care unit patients were considered. The CK-MB RIA was found to be a reliable replacement for electrophoresis, but it was nonspecific in some patients.
心肌梗死（MI）的诊断通常通过评估临床症状、心电图变化和血清酶水平来确定，特别是通过电泳检测肌酸磷酸激酶MB亚基（CK-MB）。本研究共评估了215名患者。其中102人被收入冠心病监护病房，113人被收入急诊室，在那里对他们进行了可能的心肌梗死筛查。本研究中使用的放射免疫分析（RIA）通过检测B单体来测定CK-MB同工酶的水平，该单体与CK-BB同工酶也具有100%的交叉反应性。30个样本的批内变异系数（CVs）分别为22%（均值 = 7.0 ng/ml）和11%（均值 = 47.3 ng/ml），30个样本的批间CVs分别为17%（均值 = 7.1 ng/ml）和9.2%（均值 = 49.3 ng/ml）。在评估的215名患者中，根据研究标准有21人患有心肌梗死。诊断敏感性、特异性和准确性分别为100.0%、92.8%和93.5%。仅考虑冠心病监护病房的患者时，这些值分别提高到100.0%、96.9%和97.2%。发现CK-MB RIA是电泳的可靠替代方法，但在一些患者中具有非特异性。
