潘生丁试验中QT间期离散度增加对冠心病诊断价值的探讨

目的观察冠心病患者潘生丁试验前后心电图ST段、校正QT间期(QTc)及QT间期离散度(QTd)的变化，以探讨潘生丁试验时诊断冠心病的更敏感及特异的指标。方法对30例冠心病患者(冠心病组)及32例正常者(对照组)进行潘生丁试验，记录试验前后12导联同步心电图，测量其ST段，QTc及QTd的改变。根据受试者作业特征曲线(ROC曲线)求出QTc及QTd的阳性分界点，结合传统诊断标准ST段下移≥0．1mV，分别计算其特异性及敏感性。并与“并联诊断”方法进行比较。结果以潘生丁试验诊断冠心病时，如分别以ST段下移≥0．1mv、QTc≥440ms、QTd≥40ms为标准，其特异性分别为100％、68．8％、93．8％；敏感性分别为53．3％、83．3％和87．6％。如采用“并联诊断”方法，分别以ST段下移≥0．1mV和QTc≥440ms、ST段下移≥0．1mV和QTd≥40ms、QTc≥440ms和QTd≥40ms为标准，其特异性分别为68．8％、93．8％、68．8％。敏感性分别为70．0％、96．8％、90．0％。结论在潘生丁试验时，如以传统的诊断标准(ST段下移≥0．1mV)，结合QTd≥40ms，可明显提高其诊断的敏感性而不影响其特异性，QTd≥40ms可作为潘生丁试验时诊断冠心病的一项重要参考指标。

The diagnosis value of QTd in dipyridamole test for coronary heart disease

Objective:To investigate the value of QTc and QTd combined with ECG in dipyridamole test in the diagnosis of coronary heart disease anti to determine the more sensitive and specific criteria.Method:30 patients with coronary heart disease and 32 normal controls were undergone dipyridamole test.ST segment,QTc and QTd were measured in 12 lead synchronizing ECG recorded before and during the test.The specificity andi sensitivity of each criterion were calculated according to the positive dividing point on ROC curve combined with traditional criterion of ST segment depression equal or more than 0.1 mV. This was also compared with the method of“combining diagnostic criteria”. Result:It showed that using ST segment depression ≥0.1 mV，QTc≥440 ms and QTd≥40 ms as diagnostic criteria for dipyridamole test,the specificity of the above criteria was100%, 68.8% and 93.8%,respectively, and the sensitivity, 53.3%, 83.3% and 87.6%, respectively. By combining the diagnostic criteria of ST segment depression ≥0. 1 mV and QTc≥440 ms,ST segment depression≥0.1 mV and QTd≥40 ms,and QTc≥440 ms and QTd≥40 ms,the specificity of the above criteria was 68.8%,93.8%,and 68.8%,respectively,and the sensitivity, 70.0%,96.8% and 90.0%, respectively. Conclusion: It suggested that the traditional criteria of ST segment depression ≥0.1 mV combined with QTd≥40 ms during dipyridamole test might increase the sensitivity of the diagnosis of coronary heart disease while did not significantly decrease the specificity,which suggests that QTd≥40 ms during dipyridamole test might be used as an important index in the diagnosis of coronary heart disease.